Lopez began to study dance at age three and by age 10 was discovered at a talent competition by an agent and encouraged to try an acting career. Soon after, he was cast on the short-lived sitcom "a.k.a. Pablo" (ABC, 1984), a series starring Paul Rodriguez as a Mexican-American comedian whose assimilated parents disapprove of his ethnic-based humor. Before long, Lopez was a featured supporting player on the syndicated children's music series "Kids Incorporated,” putting his dancing skills to good use from 1984 to 1986. He began landing guest roles on primetime series, including a memorable appearance in a 1987 episode of "The Golden Girls,” playing an inspiring young student of Dorothy's who risks deportation because of his prize-winning essay on coming to America. The following year Lopez made his feature debut in "Colors,” a police drama set amid gang tensions in East L.A.

In 1989, the young actor landed a role on the popular high school set Saturday morning comedy series "Saved By the Bell", playing confident jock A.C. Slater, friend and chief rival of schemer Zack. During his four seasons as Slater, Lopez won countless young fans, and graced the pages of many a teenage pinup magazine. Loyal to the franchise, Lopez starred in the specials "Saved By the Bell – Hawaiian Style" (1992), "Saved By the Bell Graduation Special" (1993) and "Saved By the Bell – Wedding in Las Vegas" (1994) as well as the short-lived 1993-1994 primetime series "Saved By the Bell: The College Years" (all NBC). Having captured the youth audience, he landed work as host of NBC's unique home viewer participatory series "Name Your Adventure" (1992-93) and the action-packed game show "Masters of the Maze" (1995) for The Family Channel.

Best known for his somewhat fluffy youth-aimed work, Lopez was featured in the dark, high school revenge NBC TV-movie "Killing Mr. Griffin", but was more impressive with a surprisingly adept and sensitive turn as the legendary Olympic diver in the USA Network presentation "Breaking the Surface: The Greg Louganis Story" (1997), based on the athlete's own memoirs. Lopez capably handled the traumas of Louganis' life, dealing with racism, homophobia and dyslexia as well as his triumphs, becoming a uniquely celebrated diver and taking four Olympic gold medals. The muscular actor lost ten pounds and sculpted his powerful wrestler's physique into a leaner diver's body for his role in the biopic, and stepped up to the acting challenge as well, proving an engaging screen presence and showing his ability to easily handle material beyond his limited "Saved by the Bell" work.

Lopez could next be seen on television with a regular role on the USA Network's crime series "Pacific Blue,” as one of a group of bike patrol officers who often go undercover to eliminate the insidious criminal element in the beach communities of Southern California. The actor joined the cast in 1998 as Bobby Cruz, the team's resident angry young man, a former LAPD officer who was ousted from the force for use of excessive force. Lopez's portrayal of the tormented Cruz subtly uncovered the character's residual rage, suffering with his parents' senseless and unavenged death at the hands of a drunk driver acquitted due to political connections.

After successfully establishing a new screen persona, Lopez returned to feature work with a starring role in the direct-to-video sci-fi thriller "Absolution" (1999) and as co-star of the higher profile action adventure "The Padre of Santa Rosa" (lensed 2000), alongside Jimmy Smits. Lopez next played a stock market savvy ex-con looking for a second chance in “Eastside” (2000), then starred in “Outta Time” (2002) as a college student who suffers a knee injury that costs him his soccer scholarship, forcing him to transport packages for a shady medical laboratory to make ends meet.

After appearing in an episode of “Nip/Tuck” (FX Network, 2003- ) as a plastic surgeon who gives Dr. Troy (Julian McMahon) liposuction, Lopez joined ten other celebrities for the third season of “Dancing With the Stars” (ABC, 2004- ), a weekly dance competition that paired professional dancers with inexperienced stars, many of whom have two left feet. Lopez displayed his considerable talents from the start, wowing the judges the first night with his take on the Cha Cha. The second round, however, all three judges scolded Lopez for taking too many liberties with the Quick Step. Nonetheless, Lopez remained one of the top dancers on the show.