Madeira Beach is a city in Pinellas County, Florida, United States, bordered on the west by the Gulf of Mexico, and on the east by St. Petersburg. As of the 2020 census, the population was 3,895. The entertainment district of John's Pass is located on the Intracoastal Waterway. The city is often referred to by locals as Mad Beach. It is named after the Portuguese island of Madeira.

Prior to European colonization, the area that makes up what is now Madeira Beach was rarely permanently inhabited. The local Tocobaga chiefdom used the land to harvest seafood, but did not live on the land.

The modern shape of Madeira Beach was formed by a hurricane, the "Gale of '48", carving out the strait now known as John's Pass. The new waterway was named after an early homesteader, John (Juan) Levique.

Several aborted attempts to settle the area occurred in the early 1900s, but it was not until 1926 that a causeway was built between the mainland and Madeira Beach, allowing for the first houses to be constructed in the area. A bridge was built crossing John's Pass a year later. Madeira Beach incorporated as a town in May 1947. The town annexed the nearby municipality of South Madeira in 1951. Significant dredging operations on the intracoastal causeway dramatically expanded the land area of Madeira Beach in the 1950s and 1960s. Additionally, the town annexed some land on mainland Pinellas in 1955 for the construction of a shopping center and a school, now Madeira Beach Fundamental School.

The town saw significant construction in the 1970s and 1980s, including the construction of many beach condos and hotels along the beach. Today, it remains a sleepy beach town, popular as a vacation destination.