Los Al is known for its success in many Varsity sports. The boys' Varsity Football team won a CIF Southern Section Division 3 title in 1991, Division 2 titles in 1992, 1993 (shared title with Esperanza,) and 2025, and won a Division 1 title in 2002. They have also reached the finals and semi-finals on numerous other occasions.
The Boys' water polo team was also CIF-SS Division II champions in fall 1999, and 2004 and were CIF-SS Masters champions in 2007.
The boys' Los Al Tennis team won the CIF SS Division I Championship in 2001 and again in 2015. After the 2015 season, multiple publications listen the Griffins as the best high school tennis team in the nation. Considering the level of competition in tennis in Southern California, this was a most notable accomplishment. It was in CIF Division I semi-finals in 1999 and 2000. From 1995 through 2001 it had a league record of 69–1, an overall record of 128–18 and produced 16 All-Orange County selections. Additionally, 55 players were honored as scholar athletes and went on to play at college level. The team received recognition from the Mayors of the cities of Los Alamitos and Seal Beach for its contribution to positive publicity.
The girls' volleyball team has won a number of CIF local and state championships. It was CIF Southern Section Division IA champions in 2002, 2004, and 2013 and won CIF Division I State championships in 2003, 2005, and 2006, and came in second 2013. In 2018, the team won the CIF Southern Section Division 2 championship and lost in the quarterfinals in the CIF Division 1 State Championships.
Girls' soccer won CIF section titles in 1996 (Div. II), 1997 (Div. I) and 2005 (Div. I). The last team was also named the No. 1 team in the nation by Student Sports Magazine. Another indicator of the success of the program was that in 2007 there were 17 Los Al alumni girls playing NCAA Division I soccer.
The Griffin Varsity Boys' soccer team won CIF-Southern Section titles in 1991, 2002, and 2026. In 2026, they also won the first-ever CIF Division III State Championships. Cooper Coleman scored the deciding goal in that State Championship Game against Watsonville. Alums Mike Munoz (2001) and Jonathan Bornstein (2002) have both made MLS rosters (LA Galaxy and Chivas USA respectively,) and Bornstein was not only the 2006 MLS Rookie of the Year Award winner, but also captained the US Men's National team roster.
The boys' Basketball team won CIF Division I-A and I-AA championships in 2006 and 2007, respectively. Los Al Basketball great Ali Ton once held the assist record at Davidson College. In 2025, the Griffins returned to the CIF SS Division 1 final, defeating Mira Costa High School 63-60 to win their first title in 18 years. Trent Minter was recognized as CIF Division 1 Player of the Year, Coach Nate Berger CIF Division 1 Coach of the Year, and Wesley Trevino made CIF Division 1 All First Team