Gerardo "Jack" Tojino Santiago is a Filipino former basketball player and coach who most recently served as head coach of UE Red Warriors.
Santiago played for Mapua, and played with future PBA superstar Alvin Patrimonio. Santiago also played in PBA teams such as Sunkist Orange Juicers, and Sta. Lucia Realtors.
Santiago previously served as lead assistant to Franz Pumaren in La Salle, Air21, and Adamson. Santiago was named as UE Red Warriors head coach on 2022. Santiago was suspended by the UAAP in 2022 after he instructed his players to intentionally harm Ricci Rivero of the UP Fighting Maroons.
Santiago is councilor of Navotas from 2013 to 2022.