Mary Mitzi Lim Cajayon-Uy, also known as Mitch Cajayon-Uy, is a Filipino politician who is the incumbent representative from the 2nd District of Caloocan in the House of Representatives of the Philippines since 2022 and previously from 2007 to 2013. She also served as the executive director of the Council for the Welfare of Children, an attached agency of the Department of Social Welfare and Development from 2017 to 2021. She also served as a city councilor of Caloocan.

Caloocan's 2nd congressional district, also known as South Caloocan district, is one of the three congressional districts of the Philippines in the city of Caloocan. It has been represented in the House of Representatives of the Philippines since 1987. The district consists of the entire South Caloocan barangays south of Circumferential Road 4 : Barangays 5 to 76 in Zones 1 to 7 and Barangays 86 to 131 in Zones 8 to 11. It is currently represented in the 19th Congress by Mary Mitzi Cajayon-Uy of Lakas–CMD.