Al-Kauthar Mosque, Islamic place of worship in Tawau, Malaysia.

Al-Kauthar Mosque stands on Jalan Persisiran beside the sea in Tawau, near the road to Sabindo Square. It has three levels: men pray on the first floor, women on the second, and the ground floor holds overflow worshippers, with movable partitions to separate them. The building cost RM 31.5 million and was finished in October 2002.

The mosque construction began in 1997 and was completed in 2002, with official inauguration taking place in 2004. This marked a major religious development for the community in the region.

The mosque's name, Al-Kauthar, refers to a river in paradise in Islamic tradition, and it is also called Masjid Besar Tawau, meaning the Great Mosque of Tawau. Worshippers use separate prayer levels for men and women, and the basement level holds overflow congregations, with movable walls that can divide the men's and women's areas.

The location sits along the beachfront, and visitors can enjoy clear views of the nearby island on good weather days. The facility is designed to accommodate large numbers of visitors and features multiple functional spaces for different activities.

The mosque has three levels: men pray on the first floor, women on the second, and the ground floor holds overflow worshippers, with movable walls to separate men and women. Worshippers can perform ablutions either at modern piped taps in separate male and female rooms or at a large water pool in the traditional village manner. A paid shoe storage area was added after repeated thefts of footwear.