Maualuga attended St. Bonaventure High School in Ventura, California where he played on a team with Lorenzo Booker.

He moved to Eureka, California before his sophomore year where he played with future Cincinnati Bengals wide receiver Maurice Purify.

[1] His team, the Eureka High School Loggers completed their perfect 13-0 season with a North Coast Section championship at the Redwood Bowl during his junior year.

Maualuga attended the University of Southern California, and played for coach Pete Carroll's USC Trojans football team from 2005 to 2008.

[2] He agreed in an arraignment diversion program that included counseling, Alcoholics Anonymous meetings and community service resulting in the charges being dismissed.

[4] Maualuga was considered a top choice for the 2008 NFL draft, but he decided to stay for his senior year in college.

At the end of the 2007 regular season, Maualuga was selected to the All-Pacific-10 Conference first team for the second year in a row by league coaches.

Some NFL scouts have compared Maualuga to former Trojan and NFL linebacker Junior Seau and former Trojan and retired Pittsburgh Steelers safety Troy Polamalu, both of Samoan descent, for their sideline-to-sideline aggressive style of defense play, and Polamalu's shared preference for displaying long Polynesian warrior-style hair tucked under their football helmet.

[14] USC linebackers Maualuga, Cushing, and Matthews were all featured on the cover of Sports Illustrated's 2009 NFL Draft Preview magazine, as all three were regarded as potential first round selections.

[16] He was projected by some, and expecting, to go 16th overall to the San Diego Chargers, who instead opted to select hybrid linebacker/defensive end Larry English out of Northern Illinois.

His family attended First Samoan Full Gospel Pentecostal Church in Waipahu and Moanalua, where Rey was a member of the FSFGPC youth group.

He spent his first year of high school in nearby Ventura before moving up to Eureka in Northern California where his father practiced ministry.

[2] Maualuga also played fictional NFL player Popo Vanauta in the 2014 baseball film Million Dollar Arm.

[31] On August 12, 2021, Maualuga was arrested for operating a motor vehicle while under the influence, criminal mischief, and wanton endangerment in Villa Hills, Kentucky.