Robert Cantu was born and raised in McAllen, Texas. He graduated from McAllen High School in 1984 and attended the University of Texas-Pan American. He later attended law school at Thurgood Marshall School of Law and has been a practicing attorney for over 20 years. He is currently the Parliamentarian of the Hidalgo County Republican Party.

He is married to Lisa Cantu and he has strong conservative values and is Pro-Life and Pro-Family. He has been involved in many community and charitable organizations such as the Knights of Columbus and has volunteered at the Food Bank.