Sixth Floor Museum at Dealey Plaza, Historical museum in downtown Dallas, United States.

The Sixth Floor Museum at Dealey Plaza occupies the sixth floor of the seven-story Texas School Book Depository, a red-brick building at Elm and Houston streets with round-arched windows and a stone panel reading "THE SCHOOL BOOK DEPOSITORY". The museum's main exhibit, John F. Kennedy and the Memory of a Nation, uses films, photographs and artifacts to document the 1963 assassination and its aftermath.

The seven-story building was built in 1901 on the foundation of an 1898 structure that burned after a lightning strike. It first served as a warehouse for plows and agricultural equipment, then housed a grocery wholesaler, and in 1963 was leased to the Texas School Book Depository Company. Dallas County acquired it after 1970 and restored the exterior to its 1901 appearance by 1981; the museum opened on February 20, 1989.

The building's name comes from the Texas School Book Depository Company, which leased it in 1963 as a textbook distribution hub with regional offices for education publishers. The museum neither encourages nor discourages conspiracy theories, and its first curator, Gary Mack (2000–2015), began as a conspiracy researcher before supporting the official conclusion that Oswald acted alone.

The museum occupies the sixth floor of the former Texas School Book Depository, reached by elevator from the ground-level entrance on Elm and Houston Streets. The exhibition is self-guided, and the sixth-floor windows overlooking Dealey Plaza remain in place, so visitors can look out at the route the motorcade took. A live webcam shows the view from the southeast corner window of the sniper's nest.

The museum holds the copyright to the Zapruder film, donated by the Zapruder family in December 1999 together with a first-generation copy made on November 22, 1963; the original camera negative stays with the National Archives. A webcam shows a live view from the sixth-floor sniper's nest.