McClennon is a surname. Notable people with the surname include:

• George McClennon (died 1937), American jazz clarinetist, singer and dancer
• James McClennon (1900–1971), English footballer
• Sheila McClennon (born 1960), British radio presenter

• St. John's basketball
• St. John's Beaumont School
• St John's Beaumont School
• St John's Beck
• St John's Bridge Island
• St John's Bridge, Lechlade
• St. Johnsbury Federal Fish Culture Station
• St. Johnsbury Historic District
• St. John's Burying Ground
• St. Johnsbury Main Street Historic District
• St. John's Business and Enterprise College
• St. John's Cadets football
• St. John's Capitals
• St. John's, Castlerigg and Wythburn
• St John's, Castlerigg and Wythburn
• St John's Castlerigg and Wythburn
• St. John's Cathedral (Albuquerque, New Mexico)
• St. John's Cathedral Block
• St. John's Cathedral (Chiayi)
• St. John's Cathedral (Korea)
• St. John's Cathedral, Nazareth
• St John's Cathedral (Oban)
• St John's Catholic Church, Campbelltown
• St. John's Catholic Church (Frederick, Maryland)
• St. John's Cemetery (disambiguation)