diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/PlainTimePrototype.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/PlainTimePrototype.cpp
index 4d83c1a477..1eb60b0275 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/PlainTimePrototype.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/PlainTimePrototype.cpp
@@ -38,6 +38,7 @@ void PlainTimePrototype::initialize(GlobalObject& global_object)
     define_native_accessor(vm.names.nanosecond, nanosecond_getter, {}, Attribute::Configurable);
 
     u8 attr = Attribute::Writable | Attribute::Configurable;
+    define_native_function(vm.names.equals, equals, 1, attr);
     define_native_function(vm.names.toPlainDateTime, to_plain_date_time, 1, attr);
     define_native_function(vm.names.getISOFields, get_iso_fields, 0, attr);
     define_native_function(vm.names.valueOf, value_of, 0, attr);
@@ -147,6 +148,48 @@ JS_DEFINE_NATIVE_FUNCTION(PlainTimePrototype::nanosecond_getter)
     return Value(temporal_time->iso_nanosecond());
 }
 
+// 4.3.16 Temporal.PlainTime.prototype.equals ( other ), https://tc39.es/proposal-temporal/#sec-temporal.plaintime.prototype.equals
+JS_DEFINE_NATIVE_FUNCTION(PlainTimePrototype::equals)
+{
+    // 1. Let temporalTime be the this value.
+    // 2. Perform ? RequireInternalSlot(temporalTime, [[InitializedTemporalTime]]).
+    auto* temporal_time = typed_this(global_object);
+    if (vm.exception())
+        return {};
+
+    // 3. Set other to ? ToTemporalTime(other).
+    auto* other = to_temporal_time(global_object, vm.argument(0));
+    if (vm.exception())
+        return {};
+
+    // 4. If temporalTime.[[ISOHour]] ≠ other.[[ISOHour]], return false.
+    if (temporal_time->iso_hour() != other->iso_hour())
+        return Value(false);
+
+    // 5. If temporalTime.[[ISOMinute]] ≠ other.[[ISOMinute]], return false.
+    if (temporal_time->iso_minute() != other->iso_minute())
+        return Value(false);
+
+    // 6. If temporalTime.[[ISOSecond]] ≠ other.[[ISOSecond]], return false.
+    if (temporal_time->iso_second() != other->iso_second())
+        return Value(false);
+
+    // 7. If temporalTime.[[ISOMillisecond]] ≠ other.[[ISOMillisecond]], return false.
+    if (temporal_time->iso_millisecond() != other->iso_millisecond())
+        return Value(false);
+
+    // 8. If temporalTime.[[ISOMicrosecond]] ≠ other.[[ISOMicrosecond]], return false.
+    if (temporal_time->iso_microsecond() != other->iso_microsecond())
+        return Value(false);
+
+    // 9. If temporalTime.[[ISONanosecond]] ≠ other.[[ISONanosecond]], return false.
+    if (temporal_time->iso_nanosecond() != other->iso_nanosecond())
+        return Value(false);
+
+    // 10. Return true.
+    return Value(true);
+}
+
 // 4.3.17 Temporal.PlainTime.prototype.toPlainDateTime ( temporalDate ), https://tc39.es/proposal-temporal/#sec-temporal.plaintime.prototype.toplaindatetime
 JS_DEFINE_NATIVE_FUNCTION(PlainTimePrototype::to_plain_date_time)
 {
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/PlainTimePrototype.h b/Userland/Libraries/LibJS/Runtime/Temporal/PlainTimePrototype.h
index f5b2f881a4..d590872bca 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/PlainTimePrototype.h
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/PlainTimePrototype.h
@@ -26,6 +26,7 @@ private:
     JS_DECLARE_NATIVE_FUNCTION(millisecond_getter);
     JS_DECLARE_NATIVE_FUNCTION(microsecond_getter);
     JS_DECLARE_NATIVE_FUNCTION(nanosecond_getter);
+    JS_DECLARE_NATIVE_FUNCTION(equals);
     JS_DECLARE_NATIVE_FUNCTION(to_plain_date_time);
     JS_DECLARE_NATIVE_FUNCTION(get_iso_fields);
     JS_DECLARE_NATIVE_FUNCTION(value_of);
diff --git a/Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainTime/PlainTime.prototype.equals.js b/Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainTime/PlainTime.prototype.equals.js
new file mode 100644
index 0000000000..595b299063
--- /dev/null
+++ b/Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainTime/PlainTime.prototype.equals.js
@@ -0,0 +1,12 @@
+describe("correct behavior", () => {
+    test("length is 1", () => {
+        expect(Temporal.PlainTime.prototype.equals).toHaveLength(1);
+    });
+
+    test("basic functionality", () => {
+        const firstPlainTime = new Temporal.PlainTime(1, 1, 1, 1, 1, 1);
+        const secondPlainTime = new Temporal.PlainTime(0, 1, 1, 1, 1, 1);
+        expect(firstPlainTime.equals(firstPlainTime));
+        expect(!secondPlainTime.equals(secondPlainTime));
+    });
+});