diff --git a/src/uu/ls/src/ls.rs b/src/uu/ls/src/ls.rs
index 9a3b98e66..44c644849 100644
--- a/src/uu/ls/src/ls.rs
+++ b/src/uu/ls/src/ls.rs
@@ -74,6 +74,7 @@ pub mod options {
         pub static TIME: &str = "t";
         pub static NONE: &str = "U";
         pub static VERSION: &str = "v";
+        pub static EXTENSION: &str = "X";
     }
     pub mod time {
         pub static ACCESS: &str = "u";
@@ -134,6 +135,7 @@ enum Sort {
     Size,
     Time,
     Version,
+    Extension,
 }
 
 enum SizeFormat {
@@ -277,6 +279,7 @@ impl Config {
                 "time" => Sort::Time,
                 "size" => Sort::Size,
                 "version" => Sort::Version,
+                "extension" => Sort::Extension,
                 // below should never happen as clap already restricts the values.
                 _ => unreachable!("Invalid field for --sort"),
             }
@@ -288,6 +291,8 @@ impl Config {
             Sort::None
         } else if options.is_present(options::sort::VERSION) {
             Sort::Version
+        } else if options.is_present(options::sort::EXTENSION) {
+            Sort::Extension
         } else {
             Sort::Name
         };
@@ -754,10 +759,10 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
         .arg(
             Arg::with_name(options::SORT)
                 .long(options::SORT)
-                .help("Sort by <field>: name, none (-U), time (-t) or size (-S)")
+                .help("Sort by <field>: name, none (-U), time (-t), size (-S) or extension (-X)")
                 .value_name("field")
                 .takes_value(true)
-                .possible_values(&["name", "none", "time", "size", "version"])
+                .possible_values(&["name", "none", "time", "size", "version", "extension"])
                 .require_equals(true)
                 .overrides_with_all(&[
                     options::SORT,
@@ -765,6 +770,7 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
                     options::sort::TIME,
                     options::sort::NONE,
                     options::sort::VERSION,
+                    options::sort::EXTENSION,
                 ])
         )
         .arg(
@@ -777,6 +783,7 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
                     options::sort::TIME,
                     options::sort::NONE,
                     options::sort::VERSION,
+                    options::sort::EXTENSION,
                 ])
         )
         .arg(
@@ -789,6 +796,7 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
                     options::sort::TIME,
                     options::sort::NONE,
                     options::sort::VERSION,
+                    options::sort::EXTENSION,
                 ])
         )
         .arg(
@@ -801,6 +809,20 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
                     options::sort::TIME,
                     options::sort::NONE,
                     options::sort::VERSION,
+                    options::sort::EXTENSION,
+                ])
+        )
+        .arg(
+            Arg::with_name(options::sort::EXTENSION)
+                .short(options::sort::EXTENSION)
+                .help("Sort alphabetically by entry extension.")
+                .overrides_with_all(&[
+                    options::SORT,
+                    options::sort::SIZE,
+                    options::sort::TIME,
+                    options::sort::NONE,
+                    options::sort::VERSION,
+                    options::sort::EXTENSION,
                 ])
         )
         .arg(
@@ -815,6 +837,7 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
                     options::sort::TIME,
                     options::sort::NONE,
                     options::sort::VERSION,
+                    options::sort::EXTENSION,
                 ])
         )
 
@@ -1149,6 +1172,12 @@ fn sort_entries(entries: &mut Vec<PathData>, config: &Config) {
             (filename_nodot.to_lowercase(), !has_dot)
         }),
         Sort::Version => entries.sort_by(|k, j| version_cmp::version_cmp(&k.p_buf, &j.p_buf)),
+        Sort::Extension => entries.sort_by(|a, b| {
+            a.p_buf
+                .extension()
+                .cmp(&b.p_buf.extension())
+                .then(a.p_buf.file_stem().cmp(&b.p_buf.file_stem()))
+        }),
         Sort::None => {}
     }
 
diff --git a/tests/by-util/test_ls.rs b/tests/by-util/test_ls.rs
index da45934e9..6a1c7764b 100644
--- a/tests/by-util/test_ls.rs
+++ b/tests/by-util/test_ls.rs
@@ -1696,3 +1696,53 @@ fn test_ls_deref_command_line_dir() {
 
     assert!(!result.stdout_str().ends_with("sym_dir"));
 }
+
+#[test]
+fn test_ls_sort_extension() {
+    let scene = TestScenario::new(util_name!());
+    let at = &scene.fixtures;
+    for filename in &[
+        "file1",
+        "file2",
+        "anotherFile",
+        ".hidden",
+        ".file.1",
+        ".file.2",
+        "file.1",
+        "file.2",
+        "anotherFile.1",
+        "anotherFile.2",
+        "file.ext",
+        "file.debug",
+        "anotherFile.ext",
+        "anotherFile.debug",
+    ] {
+        at.touch(filename);
+    }
+
+    let expected = vec![
+        ".",
+        "..",
+        ".hidden",    
+        "anotherFile",
+        "file1",
+        "file2",
+        ".file.1",
+        "anotherFile.1",
+        "file.1",
+        ".file.2",
+        "anotherFile.2",
+        "file.2",
+        "anotherFile.debug",
+        "file.debug",
+        "anotherFile.ext",
+        "file.ext",
+        "", // because of '\n' at the end of the output
+    ];
+
+    let result = scene.ucmd().arg("-1aX").run();
+    assert_eq!(result.stdout_str().split('\n').collect::<Vec<_>>(), expected,);
+
+    let result = scene.ucmd().arg("-1a").arg("--sort=extension").run();
+    assert_eq!(result.stdout_str().split('\n').collect::<Vec<_>>(), expected,);
+}