Yes and no: they are two distinct territories located on the same 37-square-mile island. St. Martin (the northern 60%) is a French overseas collectivity, while St. Maarten (the southern 40%) is a constituent country of the Kingdom of the Netherlands. They share the same physical landmass but have different "personalities": the French side is known for secluded beaches, gourmet dining, and a relaxed European vibe, while the Dutch side is famous for its vibrant nightlife, casinos, and the bustling cruise port in Philipsburg. There is no hard border between the two, so you can drive freely from one side to the other without a passport. However, they use different currencies (Euro vs. Guilder, though USD is accepted everywhere) and have separate local governments, making the island a unique "dual-nation" destination.