diff --git a/Userland/Libraries/LibJS/Runtime/CommonPropertyNames.h b/Userland/Libraries/LibJS/Runtime/CommonPropertyNames.h
index 93c6df3e0b..ad5569f174 100644
--- a/Userland/Libraries/LibJS/Runtime/CommonPropertyNames.h
+++ b/Userland/Libraries/LibJS/Runtime/CommonPropertyNames.h
@@ -382,6 +382,7 @@ namespace JS {
     P(toLowerCase)                           \
     P(toPlainDate)                           \
     P(toPlainDateTime)                       \
+    P(toPlainTime)                           \
     P(toString)                              \
     P(toTemporalInstant)                     \
     P(toTimeString)                          \
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/PlainDateTimePrototype.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/PlainDateTimePrototype.cpp
index 4566cb1c68..83fb807ad3 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/PlainDateTimePrototype.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/PlainDateTimePrototype.cpp
@@ -9,6 +9,7 @@
 #include <LibJS/Runtime/Temporal/PlainDate.h>
 #include <LibJS/Runtime/Temporal/PlainDateTime.h>
 #include <LibJS/Runtime/Temporal/PlainDateTimePrototype.h>
+#include <LibJS/Runtime/Temporal/PlainTime.h>
 
 namespace JS::Temporal {
 
@@ -52,6 +53,7 @@ void PlainDateTimePrototype::initialize(GlobalObject& global_object)
     define_native_function(vm.names.withCalendar, with_calendar, 1, attr);
     define_native_function(vm.names.valueOf, value_of, 0, attr);
     define_native_function(vm.names.toPlainDate, to_plain_date, 0, attr);
+    define_native_function(vm.names.toPlainTime, to_plain_time, 0, attr);
     define_native_function(vm.names.getISOFields, get_iso_fields, 0, attr);
 }
 
@@ -413,6 +415,19 @@ JS_DEFINE_NATIVE_FUNCTION(PlainDateTimePrototype::to_plain_date)
     return create_temporal_date(global_object, date_time->iso_year(), date_time->iso_month(), date_time->iso_day(), date_time->calendar());
 }
 
+// 5.3.40 Temporal.PlainDateTime.prototype.toPlainTime ( ), https://tc39.es/proposal-temporal/#sec-temporal.plaindatetime.prototype.toplaintime
+JS_DEFINE_NATIVE_FUNCTION(PlainDateTimePrototype::to_plain_time)
+{
+    // 1. Let dateTime be the this value.
+    // 2. Perform ? RequireInternalSlot(dateTime, [[InitializedTemporalDateTime]]).
+    auto* date_time = typed_this(global_object);
+    if (vm.exception())
+        return {};
+
+    // 3. Return ? CreateTemporalTime(dateTime.[[ISOHour]], dateTime.[[ISOMinute]], dateTime.[[ISOSecond]], dateTime.[[ISOMillisecond]], dateTime.[[ISOMicrosecond]], dateTime.[[ISONanosecond]]).
+    return create_temporal_time(global_object, date_time->iso_hour(), date_time->iso_minute(), date_time->iso_second(), date_time->iso_millisecond(), date_time->iso_microsecond(), date_time->iso_nanosecond());
+}
+
 // 5.3.41 Temporal.PlainDateTime.prototype.getISOFields ( ), https://tc39.es/proposal-temporal/#sec-temporal.plaindatetime.prototype.getisofields
 JS_DEFINE_NATIVE_FUNCTION(PlainDateTimePrototype::get_iso_fields)
 {
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/PlainDateTimePrototype.h b/Userland/Libraries/LibJS/Runtime/Temporal/PlainDateTimePrototype.h
index ca805461bc..ee541c62ba 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/PlainDateTimePrototype.h
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/PlainDateTimePrototype.h
@@ -42,6 +42,7 @@ private:
     JS_DECLARE_NATIVE_FUNCTION(with_calendar);
     JS_DECLARE_NATIVE_FUNCTION(value_of);
     JS_DECLARE_NATIVE_FUNCTION(to_plain_date);
+    JS_DECLARE_NATIVE_FUNCTION(to_plain_time);
     JS_DECLARE_NATIVE_FUNCTION(get_iso_fields);
 };
 
diff --git a/Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainDateTime/PlainDateTime.prototype.toPlainTime.js b/Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainDateTime/PlainDateTime.prototype.toPlainTime.js
new file mode 100644
index 0000000000..feb4839dc9
--- /dev/null
+++ b/Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainDateTime/PlainDateTime.prototype.toPlainTime.js
@@ -0,0 +1,16 @@
+describe("normal behavior", () => {
+    test("length is 0", () => {
+        expect(Temporal.PlainDateTime.prototype.toPlainTime).toHaveLength(0);
+    });
+
+    test("basic functionality", () => {
+        const plainDateTime = new Temporal.PlainDateTime(2021, 7, 31, 0, 32, 18, 123, 456, 789);
+        const plainTime = plainDateTime.toPlainTime();
+        expect(plainTime.hour).toBe(0);
+        expect(plainTime.minute).toBe(32);
+        expect(plainTime.second).toBe(18);
+        expect(plainTime.millisecond).toBe(123);
+        expect(plainTime.microsecond).toBe(456);
+        expect(plainTime.nanosecond).toBe(789);
+    });
+});