Mangyshlak or Mangghyshlaq Peninsula (Kazakh: Маңғыстау (Маңғышлақ) түбегі, romanized: Mañğystau (Mañğyşlaq) tübegı; Russian: Полуостров Мангышла́к, romanized: Poluostrov Mangyshlák) is a large peninsula located in western Kazakhstan.

The Tyuleniy Archipelago lies off the northern shores of the peninsula.

The area is between desert and semidesert with a harsh continental dry climate.

Geologically, the Mangyshlak Peninsula is part of the Ustyurt Plateau.

The peninsula's name stems from Ming Qishlaq, which means "1000 winter encampments" in Turkic languages.