diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f38a45f..7d4dcb4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -124,4 +124,4 @@ jobs:
         ## flags: IntegrationTests, UnitTests, ${{ steps.vars.outputs.CODECOV_FLAGS }}
         flags: ${{ steps.vars.outputs.CODECOV_FLAGS }}
         name: codecov-umbrella
-        fail_ci_if_error: false
+        fail_ci_if_error: false
\ No newline at end of file
diff --git a/Cargo.lock b/Cargo.lock
index db2fdd4..f9b1c5f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -67,12 +67,44 @@ version = "1.0.102"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7f202df86484c868dbad7eaa557ef785d5c66295e41b460ef922eca0723b842c"
 
+[[package]]
+name = "assert_cmd"
+version = "2.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2aa3a22042e45de04255c7bf3626e239f450200fd0493c1e382263544b20aea6"
+dependencies = [
+ "anstyle",
+ "bstr",
+ "libc",
+ "predicates",
+ "predicates-core",
+ "predicates-tree",
+ "wait-timeout",
+]
+
+[[package]]
+name = "autocfg"
+version = "1.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2032f911046de80f0a198e0901378627c33f59ea0ac00e363d481118bd70a53"
+
 [[package]]
 name = "bitflags"
 version = "2.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "843867be96c8daad0d758b57df9392b6d8d271134fce549de6ce169ff98a92af"
 
+[[package]]
+name = "bstr"
+version = "1.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "63044e1ae8e69f3b5a92c736ca6269b8d12fa7efe39bf34ddb06d102cf0e2cab"
+dependencies = [
+ "memchr",
+ "regex-automata",
+ "serde",
+]
+
 [[package]]
 name = "cfg-if"
 version = "1.0.4"
@@ -183,6 +215,12 @@ version = "0.1.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "56254986775e3233ffa9c4d7d3faaf6d36a2c09d30b20687e9f88bc8bafc16c8"
 
+[[package]]
+name = "difflib"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6184e33543162437515c2e2b48714794e37845ec9851711914eec9d308f6ebe8"
+
 [[package]]
 name = "displaydoc"
 version = "0.2.5"
@@ -228,6 +266,15 @@ version = "2.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9f1f227452a390804cdb637b74a86990f2a7d7ba4b7d5693aac9b4dd6defd8d6"
 
+[[package]]
+name = "float-cmp"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b09cf3155332e944990140d967ff5eceb70df778b34f77d8075db46e4704e6d8"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "fluent"
 version = "0.17.0"
@@ -330,6 +377,7 @@ checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"
 name = "hostname"
 version = "0.0.1"
 dependencies = [
+ "assert_cmd",
  "clap",
  "clap_complete",
  "clap_mangen",
@@ -337,6 +385,7 @@ dependencies = [
  "libc",
  "phf",
  "phf_codegen",
+ "predicates",
  "pretty_assertions",
  "procfs",
  "rand",
@@ -494,12 +543,27 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "normalize-line-endings"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "61807f77802ff30975e01f4f071c8ba10c022052f98b3294119f3e615d13e5be"
+
 [[package]]
 name = "num-conv"
 version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c6673768db2d862beb9b39a78fdcb1a69439615d5794a1be50caa9bc92c81967"
 
+[[package]]
+name = "num-traits"
+version = "0.2.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "071dfc062690e90b734c0b2273ce72ad0ffa95f0c74596bc250dcfd960262841"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "num_threads"
 version = "0.1.7"
@@ -590,6 +654,36 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "439ee305def115ba05938db6eb1644ff94165c5ab5e9420d1c1bcedbba909391"
 
+[[package]]
+name = "predicates"
+version = "3.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ada8f2932f28a27ee7b70dd6c1c39ea0675c55a36879ab92f3a715eaa1e63cfe"
+dependencies = [
+ "anstyle",
+ "difflib",
+ "float-cmp",
+ "normalize-line-endings",
+ "predicates-core",
+ "regex",
+]
+
+[[package]]
+name = "predicates-core"
+version = "1.0.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cad38746f3166b4031b1a0d39ad9f954dd291e7854fcc0eed52ee41a0b50d144"
+
+[[package]]
+name = "predicates-tree"
+version = "1.0.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d0de1b847b39c8131db0467e9df1ff60e6d0562ab8e9a16e568ad0fdb372e2f2"
+dependencies = [
+ "predicates-core",
+ "termtree",
+]
+
 [[package]]
 name = "pretty_assertions"
 version = "1.4.1"
@@ -858,6 +952,12 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "termtree"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f50febec83f5ee1df3015341d8bd429f2d1cc62bcba7ea2076759d315084683"
+
 [[package]]
 name = "textwrap"
 version = "0.16.2"
@@ -1053,6 +1153,15 @@ dependencies = [
  "xattr",
 ]
 
+[[package]]
+name = "wait-timeout"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09ac3b126d3914f9849036f826e054cbabdc8519970b8998ddaf3b5bd3c65f11"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "wasip2"
 version = "1.0.2+wasi-0.2.9"
diff --git a/Cargo.toml b/Cargo.toml
index 27a181a..968be7c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -65,6 +65,8 @@ uucore = { workspace = true }
 
 #
 hostname = { optional = true, version = "0.0.1", package = "uu_hostname", path = "src/uu/hostname" }
+predicates = "3.1.4"
+assert_cmd = "2.1.2"
 
 [dev-dependencies]
 ctor = { workspace = true }
@@ -91,6 +93,22 @@ phf_codegen = { workspace = true }
 name = "hostname"
 path = "src/bin/hostname.rs"
 
+[[bin]]
+name = "domainname"
+path = "src/uu/domainname/src/main.rs"
+
+[[bin]]
+name = "dnsdomainname"
+path = "src/uu/dnsdomainname/src/main.rs"
+
+[[bin]]
+name = "nisdomainname"
+path = "src/uu/nisdomainname/src/main.rs"
+
+[[bin]]
+name= "ypdomainname"
+path = "src/uu/ypdomainname/src/main.rs"
+
 [[bin]]
 name = "uudoc"
 path = "src/bin/uudoc.rs"
diff --git a/src/uu/dnsdomainname/src/main.rs b/src/uu/dnsdomainname/src/main.rs
new file mode 100644
index 0000000..4ddcfef
--- /dev/null
+++ b/src/uu/dnsdomainname/src/main.rs
@@ -0,0 +1,12 @@
+// Wrapper binary: dnsdomainname -> hostname -d
+fn main() {
+    uucore::panic::mute_sigpipe_panic();
+
+    use std::ffi::OsString;
+    use std::process;
+
+    let args = std::env::args_os().skip(1);
+    let iter = (vec![OsString::from("hostname"), OsString::from("-d")].into_iter()).chain(args);
+
+    process::exit(hostname::uumain(iter));
+}
diff --git a/src/uu/domainname/src/main.rs b/src/uu/domainname/src/main.rs
new file mode 100644
index 0000000..2d8f3ca
--- /dev/null
+++ b/src/uu/domainname/src/main.rs
@@ -0,0 +1,12 @@
+// Wrapper binary: domainname -> hostname -y
+fn main() {
+    uucore::panic::mute_sigpipe_panic();
+
+    use std::ffi::OsString;
+    use std::process;
+
+    let args = std::env::args_os().skip(1);
+    let iter = (vec![OsString::from("hostname"), OsString::from("-y")].into_iter()).chain(args);
+
+    process::exit(hostname::uumain(iter));
+}
diff --git a/src/uu/hostname/src/change.rs b/src/uu/hostname/src/change.rs
index 7497aec..6466c84 100644
--- a/src/uu/hostname/src/change.rs
+++ b/src/uu/hostname/src/change.rs
@@ -9,6 +9,6 @@ pub(crate) mod unix;
 pub(crate) mod windows;
 
 #[cfg(not(target_family = "windows"))]
-pub(crate) use unix::{from_argument, from_file};
+pub(crate) use unix::{from_argument, from_argument_nis, from_file, from_file_nis};
 #[cfg(target_family = "windows")]
 pub(crate) use windows::{from_argument, from_file};
diff --git a/src/uu/hostname/src/change/unix.rs b/src/uu/hostname/src/change/unix.rs
index d12cda2..93e1b17 100644
--- a/src/uu/hostname/src/change/unix.rs
+++ b/src/uu/hostname/src/change/unix.rs
@@ -10,13 +10,17 @@ use std::path::Path;
 use uucore::error::UResult;
 
 use crate::errors::HostNameError;
-use crate::net::set_host_name;
+use crate::net::{set_domain_name, set_host_name};
 use crate::utils::parse_host_name_file;
 
 pub(crate) fn from_file(path: &Path) -> UResult<()> {
     parse_host_name_file(path).map(Cow::Owned).and_then(run)
 }
 
+pub(crate) fn from_file_nis(path: &Path) -> UResult<()> {
+    parse_host_name_file(path).map(Cow::Owned).and_then(run_nis)
+}
+
 pub(crate) fn from_argument(host_name: &OsStr) -> UResult<()> {
     #[cfg(target_family = "unix")]
     let host_name = {
@@ -33,6 +37,22 @@ pub(crate) fn from_argument(host_name: &OsStr) -> UResult<()> {
     run(host_name)
 }
 
+pub(crate) fn from_argument_nis(domain_name: &OsStr) -> UResult<()> {
+    #[cfg(target_family = "unix")]
+    let domain_name = {
+        use std::os::unix::ffi::OsStrExt;
+        Cow::Borrowed(domain_name.as_bytes())
+    };
+
+    #[cfg(target_family = "wasm")]
+    let domain_name = {
+        use std::os::wasm::ffi::OsStrExt;
+        Cow::Borrowed(domain_name.as_bytes())
+    };
+
+    run_nis(domain_name)
+}
+
 fn run(mut host_name: Cow<[u8]>) -> UResult<()> {
     // Trim white space.
     match &mut host_name {
@@ -54,6 +74,32 @@ fn run(mut host_name: Cow<[u8]>) -> UResult<()> {
     set_host_name(&host_name)
 }
 
+fn run_nis(mut domain_name: Cow<[u8]>) -> UResult<()> {
+    match &mut domain_name {
+        Cow::Borrowed(name) => *name = name.trim_ascii(),
+
+        Cow::Owned(name) => {
+            while name.first().is_some_and(u8::is_ascii_whitespace) {
+                name.remove(0);
+            }
+
+            while name.last().is_some_and(u8::is_ascii_whitespace) {
+                name.pop();
+            }
+        }
+    };
+
+    let domain_name = validate_domain_name(domain_name)?;
+    set_domain_name(&domain_name)
+}
+
+fn validate_domain_name(domain_name: Cow<[u8]>) -> Result<CString, HostNameError> {
+    if domain_name.is_empty() {
+        return Err(HostNameError::InvalidHostName);
+    }
+    CString::new(domain_name.into_owned()).map_err(|_| HostNameError::InvalidHostName)
+}
+
 fn validate_host_name(host_name: Cow<[u8]>) -> Result<CString, HostNameError> {
     // Rules:
     // - The only allowed prefix and suffix characters are alphanumeric.
diff --git a/src/uu/hostname/src/errors.rs b/src/uu/hostname/src/errors.rs
index fe85bd0..ecf3239 100644
--- a/src/uu/hostname/src/errors.rs
+++ b/src/uu/hostname/src/errors.rs
@@ -14,6 +14,8 @@ pub enum HostNameError {
     NoLocalDomainName,
     SetHostNameDenied,
     #[cfg(not(target_family = "windows"))]
+    SetDomainNameDenied,
+    #[cfg(not(target_family = "windows"))]
     GetNameOrAddrInfo(GetNameOrAddrInfoError),
 }
 
@@ -25,6 +27,8 @@ impl fmt::Display for HostNameError {
             Self::NoLocalDomainName => write!(f, "local domain name not set"),
             Self::SetHostNameDenied => write!(f, "you must be root to change the host name"),
             #[cfg(not(target_family = "windows"))]
+            Self::SetDomainNameDenied => write!(f, "you must be root to change the domain name"),
+            #[cfg(not(target_family = "windows"))]
             Self::GetNameOrAddrInfo(r) => write!(f, "{r}"),
         }
     }
diff --git a/src/uu/hostname/src/hostname.rs b/src/uu/hostname/src/hostname.rs
index d34bb3c..1225700 100644
--- a/src/uu/hostname/src/hostname.rs
+++ b/src/uu/hostname/src/hostname.rs
@@ -38,14 +38,24 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
 
     let _net_lib_guard = net::LibraryGuard::load()?;
 
-    if args.contains_id("set-group") {
+    if args.contains_id(options::FILE) || args.contains_id(options::HOSTNAME) {
+        #[cfg(not(target_family = "windows"))]
+        let nis_mode = args.get_flag(options::NIS);
         if let Some(path) = args.get_one::<PathBuf>(options::FILE) {
+            #[cfg(not(target_family = "windows"))]
+            if nis_mode {
+                return change::from_file_nis(path);
+            }
             change::from_file(path)
         } else {
             let host_name = args
                 .get_one::<OsString>(options::HOSTNAME)
                 .expect("hostname must be specified");
 
+            #[cfg(not(target_family = "windows"))]
+            if nis_mode {
+                return change::from_argument_nis(host_name);
+            }
             change::from_argument(host_name)
         }
     } else {
@@ -176,11 +186,15 @@ hostname {-V|--version}";
                     options::IP_ADDRESS,
                     options::ALL_IP_ADDRESSES,
                     options::SHORT,
-                    options::NIS,
                 ])
                 .multiple(false)
                 .conflicts_with("set-group"),
         )
+        .group(
+            ArgGroup::new("nis-group")
+                .args([options::NIS])
+                .conflicts_with("get-group"),
+        )
         .group(
             ArgGroup::new("set-group")
                 .args([options::BOOT, options::FILE, options::HOSTNAME])
diff --git a/src/uu/hostname/src/net/unix.rs b/src/uu/hostname/src/net/unix.rs
index 0e72958..ba7d5c7 100644
--- a/src/uu/hostname/src/net/unix.rs
+++ b/src/uu/hostname/src/net/unix.rs
@@ -113,6 +113,43 @@ pub(crate) fn short_host_name() -> std::io::Result<CString> {
     Ok(unsafe { CString::from_vec_with_nul_unchecked(bytes) })
 }
 
+pub(crate) fn set_domain_name(domain_name: &CStr) -> UResult<()> {
+    use std::io::{Error, ErrorKind};
+
+    #[cfg(any(
+        target_os = "dragonfly",
+        target_os = "freebsd",
+        target_os = "illumos",
+        target_os = "ios",
+        target_os = "macos",
+        target_os = "solaris",
+    ))]
+    let Ok(domain_name_len) = c_int::try_from(domain_name.count_bytes()) else {
+        return Err(Box::new(HostNameError::HostNameTooLong));
+    };
+
+    #[cfg(not(any(
+        target_os = "dragonfly",
+        target_os = "freebsd",
+        target_os = "illumos",
+        target_os = "ios",
+        target_os = "macos",
+        target_os = "solaris",
+    )))]
+    let domain_name_len = domain_name.count_bytes();
+
+    if unsafe { libc::setdomainname(domain_name.as_ptr(), domain_name_len) } != -1 {
+        return Ok(());
+    }
+
+    let err = Error::last_os_error();
+    match err.kind() {
+        ErrorKind::PermissionDenied => Err(Box::new(HostNameError::SetDomainNameDenied)),
+        ErrorKind::InvalidInput => Err(Box::new(HostNameError::HostNameTooLong)),
+        _ => Err(err.into()),
+    }
+}
+
 pub(crate) fn set_host_name(host_name: &CStr) -> UResult<()> {
     use std::io::{Error, ErrorKind};
 
diff --git a/src/uu/nisdomainname/src/main.rs b/src/uu/nisdomainname/src/main.rs
new file mode 100644
index 0000000..27b0974
--- /dev/null
+++ b/src/uu/nisdomainname/src/main.rs
@@ -0,0 +1,12 @@
+// Wrapper binary: nisdomainname -> hostname -y (visible alias)
+fn main() {
+    uucore::panic::mute_sigpipe_panic();
+
+    use std::ffi::OsString;
+    use std::process;
+
+    let args = std::env::args_os().skip(1);
+    let iter = (vec![OsString::from("hostname"), OsString::from("-y")].into_iter()).chain(args);
+
+    process::exit(hostname::uumain(iter));
+}
diff --git a/src/uu/ypdomainname/src/main.rs b/src/uu/ypdomainname/src/main.rs
new file mode 100644
index 0000000..d83cbeb
--- /dev/null
+++ b/src/uu/ypdomainname/src/main.rs
@@ -0,0 +1,12 @@
+// Wrapper binary: ypdomainname -> hostname -y
+fn main() {
+    uucore::panic::mute_sigpipe_panic();
+
+    use std::ffi::OsString;
+    use std::process;
+
+    let args = std::env::args_os().skip(1);
+    let iter = (vec![OsString::from("hostname"), OsString::from("-y")].into_iter()).chain(args);
+
+    process::exit(hostname::uumain(iter));
+}
diff --git a/tests/by-util/test_hostname.rs b/tests/by-util/test_hostname.rs
deleted file mode 100644
index ed52ea7..0000000
--- a/tests/by-util/test_hostname.rs
+++ /dev/null
@@ -1,11 +0,0 @@
-// This file is part of the uutils hostname package.
-//
-// For the full copyright and license information, please view the LICENSE
-// file that was distributed with this source code.
-
-use uutests::new_ucmd;
-
-#[test]
-fn test_invalid_arg() {
-    new_ucmd!().arg("--definitely-invalid").fails().code_is(1);
-}
diff --git a/tests/by_util/domainname.rs b/tests/by_util/domainname.rs
new file mode 100644
index 0000000..93cde26
--- /dev/null
+++ b/tests/by_util/domainname.rs
@@ -0,0 +1,65 @@
+// Tests for the domainname utilities: dnsdomainname, domainname, nisdomainname, and ypdomainname wrapper binaries,
+// These binaries are built from src/uu/*/src/main.rs and delegates to hostname.
+
+use assert_cmd::Command;
+use predicates::prelude::*;
+
+/// Assert that `--help` succeeds and prints either the binary name or Usage text
+fn assert_help(bin: &str) {
+    Command::cargo_bin(bin)
+        .unwrap()
+        .arg("--help")
+        .assert()
+        .success()
+        .stdout(predicate::str::contains(bin).or(predicate::str::contains("Usage")));
+}
+
+/// Assert that `--version` succeeds and prints the binary name
+fn assert_version(bin: &str) {
+    Command::cargo_bin(bin)
+        .unwrap()
+        .arg("--version")
+        .assert()
+        .success()
+        .stdout(predicate::str::contains(bin));
+}
+
+#[test]
+fn dnsdomainname_help() {
+    assert_help("dnsdomainname");
+}
+
+#[test]
+fn domainname_help() {
+    assert_help("domainname");
+}
+
+#[test]
+fn nisdomainname_help() {
+    assert_help("nisdomainname");
+}
+
+#[test]
+fn ypdomainname_help() {
+    assert_help("ypdomainname");
+}
+
+#[test]
+fn dnsdomainname_version() {
+    assert_version("dnsdomainname");
+}
+
+#[test]
+fn domainname_version() {
+    assert_version("domainname");
+}
+
+#[test]
+fn nisdomainname_version() {
+    assert_version("nisdomainname");
+}
+
+#[test]
+fn ypdomainname_version() {
+    assert_version("ypdomainname");
+}
diff --git a/tests/by_util/hostname.rs b/tests/by_util/hostname.rs
new file mode 100644
index 0000000..5505a7f
--- /dev/null
+++ b/tests/by_util/hostname.rs
@@ -0,0 +1,27 @@
+use uutests::new_ucmd;
+
+pub const TESTS_BINARY: &str = env!("CARGO_BIN_EXE_hostname");
+
+// Use the ctor attribute to run this function before any tests
+#[ctor::ctor(unsafe)]
+fn init() {
+    unsafe {
+        // Necessary for uutests to be able to find the binary
+        std::env::set_var("UUTESTS_BINARY_PATH", TESTS_BINARY);
+    }
+}
+
+#[test]
+fn test_invalid_arg() {
+    new_ucmd!().arg("--definitely-invalid").fails().code_is(1);
+}
+
+#[test]
+fn test_help_flag() {
+    new_ucmd!().arg("--help").succeeds();
+}
+
+#[test]
+fn test_version_flag() {
+    new_ucmd!().arg("--version").succeeds();
+}
diff --git a/tests/tests.rs b/tests/tests.rs
index 4e3a28b..3f75a52 100644
--- a/tests/tests.rs
+++ b/tests/tests.rs
@@ -16,5 +16,8 @@ fn init() {
 }
 
 #[cfg(feature = "hostname")]
-#[path = "by-util/test_hostname.rs"]
+#[path = "by_util/hostname.rs"]
 mod test_hostname;
+
+#[path = "by_util/domainname.rs"]
+mod test_domainname;