The Zahir Mosque is Kedah's state mosque. It is located in the heart of Alor Star, the state capital of Kedah, Malaysia.
The mosque was built in 1912, a contributory effort of YTM Tunku Mahmud Ibni Almarhum Sultan Tajuddin Mukarram Shah. The site of this mosque was the cemetery of Kedah warriors who had died while defending Kedah from the Siamese in 1821. The architecture of the mosque was inspired by the Azizi Mosque in Tanjung Pura, Langkat Sultanate (present-day North Sumatra). This mosque is enhanced with five prime large domes symbolizing the Five Pillars of Islam.
Its official opening ceremony was held on Friday, 15 October 1915 by the late HRH Sultan Abdul Hamid Halim Shah. Tunku Mahmud read the Friday sermon while HRH Sultan Abdul Hamid Shah led the Friday prayer. Behind Zahir Mosque is the Syariah Court building complex and a Pre-School for Children aged below 6 years old.