The Malcolm X Shabazz High School Bulldogs compete in the Super Essex Conference, which is comprised of public and private high schools in Essex County and was established following a reorganization of sports leagues in Northern New Jersey by the New Jersey State Interscholastic Athletic Association (NJSIAA).Before the 2009 restructuring, the school had previously participated in the Watchung Conference, which included high schools in Essex, Hudson and Union counties in northern New Jersey. With 334 students in grades 10-12, the school was classified by the NJSIAA for the 2019–20 school year as Group I for most athletic competition purposes, which included schools with an enrollment of 75 to 476 students in that grade range. The football team competes in the National Red division of the North Jersey Super Football Conference, which includes 112 schools competing in 20 divisions, making it the nation's biggest football-only high school sports league. The school was classified by the NJSIAA as Group I North for football for 2018–2020.Varsity sports include basketball, volleyball, track and field, football, soccer, wrestling, golf, baseball and softball

The boys' basketball team won the Group III state championship in 1979 (vs. Long Branch High School), 1995 (vs. Rancocas Valley Regional High School), 1997 (vs. Steinert High School), 2001 (vs. Camden High School) and 2005 (vs. Camden), and the 2010 Group II title (vs. Pequannock Township High School); as South Side High School, the boys' basketball team won the Group III title in 1962 (vs. Neptune High School), 1965 (vs. South Plainfield High School), 1969 (vs. Lincoln High School) and 1971 (vs. Ocean Township High School). Lonnie Wright led the 1962 team to the Group III title with a 72-52 win against a Neptune team that came into the championship game with a 25-0 record.In 1995, the team won the Group III state title on a basket scored with just over three seconds left in the game to defeat Rancocas Valley by a score of 60-59 in the championship game. The team won the 2001 North II, Group III state sectional title with a 56–45 win against Cranford High School. The team won the 2005 Group III state championship, defeating Ramapo High School 64–59 in the semifinals and Camden High School 76–58 in the championship game. The team won the 2006 North II Group III state championships. In the Group III state tournament, the team knocked off North I Group III champion Northern Valley Regional High School at Old Tappan 77–68 in the semifinals, before falling to Hamilton High School 66–34 in the Group III championship game at Rutgers University.

The girls' basketball team won the Group III state championship in 1983 (vs. Sterling High School), 2003 and 2004 (vs. Willingboro High School both years), 2006 (vs. Monmouth Regional High School), 2008 (vs. Ocean City High School), 2009 (vs. Neptune High School), the Group II title in 2010 (vs. Chatham High School), 2011 (vs. Pascack Hills High School), 2012 (vs. Point Pleasant Borough High School) and 2013 (vs. Willingboro High School), and won the Group I title in 2014 (vs. Haddon Township High School); the 11 state championships and 14 appearances by the girls' basketball program in title games are the most of any public school in the state and the five consecutive titles from 2010 to 2014 is tied for the longest streak by a public school program. The girls' basketball team won the 2003 Tournament of Champions, defeating Marlboro High School 48–45 in the tournament final. After four consecutive titles in Group II, the team won the 2014 Group I title with an 80-49 win against Haddon Township in the championship game. The football team won the North II Group I state sectional championship in 2014 and 2017. The team defeated Dunellen High School by a score of 14–6 to win the program's first championship and the first title for a Newark high school since 2007. In 2017, the team defeated the top-seeded Weequahic High School by a score of 35-0 in the North II Group I state sectional final played at Kean University, in a rematch of the 2016 final that had been won by Weequahic. 2009 marked the return of the Thanksgiving Day game called the "Soul Bowl" between Weequahic and Shabazz High School, which had last been played in 1993 and had been in abeyance due to the two schools being placed in different athletic conferences. The 2011 game was the 29th between the two teams, ending in a 27-20 win for Weequahic, which won its fifth consecutive defeat of Shabazz. The intra-district football rivalry with Weequahic was ranked third on NJ.com's 2017 list "Ranking the 31 fiercest rivalries in N.J. HS football". Shabazz leads the series with an overall record of 35-28-6 through the 2017 season. The boys track team won the Group I spring track state championship in 2018.