Daniel Gregg Santiago (born June 24, 1976) is an American-born Puerto Rican professional basketball player for the Cangrejeros de Santurce. A center, he had a collegiate career in the NCAA and NAIA. His professional career saw him play in the NBA, the Baloncesto Superior Nacional of Puerto Rico, and overseas. Santiago has played for the Puerto Rican national team since 1998 until 2014, including been part of the 2004 team that defeated the United States at the 2004 Olympic Games in Greece.

Santiago attended and played Junior College basketball at New Mexico Military Institute in Roswell, New Mexico and played NCAA Division I basketball at the University of New Mexico. He finished up his collegiate career at the NAIA school of Saint Vincent College in Latrobe, Pennsylvania, where he was named NAIA player of the year.

In Puerto Rico, Santiago played professionally on the National Superior Basketball League with the Vaqueros, helping the team to various national championships and tournament finals.