The Sultan Salahuddin Abdul Aziz Shah Mosque (Malay: Masjid Sultan Salahuddin Abdul Aziz) is the state mosque of Selangor, Malaysia. It is located in Shah Alam. It is the country's largest mosque and also the second largest mosque in Southeast Asia after Istiqlal Mosque in Jakarta, Indonesia. Its most distinguishing feature is its large blue and silver dome. The mosque has four minarets, one erected at each of the corners.

The mosque was commissioned by the late Sultan Salahuddin Abdul Aziz, when he declared Shah Alam as the new capital of Selangor on 14 February 1974. Construction began in 1982 and finished on 11 March 1988. The Mosque is also known as the Blue Mosque owing to its blue dome. The building has the distinction of having the largest religious dome in the world, it measures 51.2 m (167 ft) in diameter and reaches 106.7 m (350 ft) above ground level. The four minarets, each reaching 142.3 m (460 ft) above ground level are the 2nd tallest in the world, the distinction of the world's highest being held by the Hassan II Mosque (Arabic: مسجد الحسن الثاني) in Casablanca, Morocco. In its early years, the mosque was listed in the Guinness World Records as having the tallest minaret in the world before being supplanted by the 210 m (689 ft) at the Hassan II Mosque when that structure was inaugurated in August 1993. The Blue Mosque (Masjid Sultan Salahuddin Abdul Aziz) does however still maintain the distinction of having the world's tallest group of minarets as the set of four each stand at 142.3 m (460 ft) above ground level.