Hel Peninsula (Polish pronunciation: [xɛl] ⓘ; Polish: Mierzeja Helska, Półwysep Helski; Kashubian: Hélskô Sztremlëzna; German: Halbinsel Hela or Putziger Nehrung) is a 35-kilometre-long (22 mi) sand bar peninsula in northern Poland separating the Bay of Puck from the open Baltic Sea.

A road and a railroad run along the peninsula from the mainland to the town at the furthest point, Hel, a popular tourist destination.

In the course of the Battle of Hel in 1939, Polish forces dynamited the peninsula at one point and turned it into an island.

Hel peninsula remained in German hands until the end of World War II, when the defending forces surrendered on 14 May 1945, six days after Germany capitulated.

Many of the fortifications and batteries are open to tourists today, but some areas of the peninsula still belong to the Polish Armed Forces.