Filemon Lagman (March 17, 1953—February 6, 2001), popularly known as Ka Popoy was a revolutionary socialist and workers' leader in the Philippines. He split with the Communist Party of the Philippines in 1991, and became the president of the socialist workers group Bukluran ng Manggagawang Pilipino (BMP). He was the first prominent victim of a political assassination under the presidency of Gloria Macapagal-Arroyo.
