In the 19th century and early 20th century, hundreds of thousands of people used the Hudson for swimming -- from docks, amusement park beaches and floating pools.

Historically, the Hudson River was a popular swimming destination for New Yorkers and Hudson Valley residents throughout the 19th and early 20th centuries, with numerous "floating baths" and beaches lining its shores. However, by the mid-20th century, heavy industrial pollution and the dumping of raw sewage made the water hazardous to human health, leading to widespread bans on swimming. In recent decades, the passage of the Clean Water Act and extensive restoration efforts have significantly improved the river's water quality. While it is not yet advisable to jump in anywhere—especially after heavy rains when "combined sewer overflows" can spike bacteria levels—swimming has seen a modern resurgence. Organizations now host organized "open water" swims, and several official beaches, such as Kingston Point Beach and Croton Point Park, allow for safe, monitored swimming. In 2023 and 2024, high-profile endurance swimmers like Lewis Pugh and Christopher Swain swam the entire length of the river to highlight its recovery, though they still had to be wary of "invisible hazards" like PCBs in the sediment near the northern industrial sites.