diff --git a/build/moz.configure/toolchain.configure b/build/moz.configure/toolchain.configure
--- a/build/moz.configure/toolchain.configure
+++ b/build/moz.configure/toolchain.configure
@@ -1511,11 +1511,11 @@
 
 
 option(
     "--enable-linker",
     nargs=1,
-    help="Select the linker {bfd, gold, ld64, lld, lld-*}{|}",
+    help="Select the linker {bfd, gold, ld64, lld, lld-*, mold}{|}",
     default=enable_linker_default,
     when=is_linker_option_enabled,
 )
 
 
@@ -1546,11 +1546,11 @@
 
     def is_valid_linker(linker):
         if target.kernel == "Darwin":
             valid_linkers = ("ld64", "lld")
         else:
-            valid_linkers = ("bfd", "gold", "lld")
+            valid_linkers = ("bfd", "gold", "lld", "mold")
         if linker in valid_linkers:
             return True
         if "lld" in valid_linkers and linker.startswith("lld-"):
             return True
         return False
@@ -1591,10 +1591,13 @@
             kind = "ld64"
 
         elif retcode != 0:
             return None
 
+        elif "mold" in stdout:
+            kind = "mold"
+
         elif "GNU ld" in stdout:
             # We are using the normal linker
             kind = "bfd"
 
         elif "GNU gold" in stdout:
@@ -1697,11 +1700,11 @@
 # There's a wrinkle with MinGW: linker configuration is not enabled, so
 # `select_linker` is never invoked.  Hard-code around it.
 @depends(select_linker, target, c_compiler)
 def gcc_use_gnu_ld(select_linker, target, c_compiler):
     if select_linker is not None and target.kernel != "Darwin":
-        return select_linker.KIND in ("bfd", "gold", "lld")
+        return select_linker.KIND in ("bfd", "gold", "lld", "mold")
     if target.kernel == "WINNT" and c_compiler.type == "clang":
         return True
     return None
 
 
diff --git a/toolkit/moz.configure b/toolkit/moz.configure
--- a/toolkit/moz.configure
+++ b/toolkit/moz.configure
@@ -1444,11 +1444,11 @@
         )
 
     @depends("--enable-release", enable_linker)
     def default_elfhack(release, linker):
         # Disable elfhack when explicitly building with --enable-linker=lld
-        if linker and linker.origin != "default" and linker[0] == "lld":
+        if linker and linker.origin != "default" and linker[0] in ("lld", "mold"):
             return False
         return bool(release)
 
     with only_when(has_elfhack):
         option(