Lake Forest High School participates in athletics in the Henlopen Conference and is one of the smaller high schools based on enrollment, thereby competing in the Henlopen South.
Football
Lake Forest has a football tradition that dates back to the 1980s, when they won several conference championships. They also won the Division II state title in 1995. Lately the football program has not managed to live up to its tradition, but is hoping to turn around under Head CoachFreddie Johnson and his staff. Lake Forest High School has a long-standing football rivalry with Henlopen North rival Milford High School, the yearly Battle of the Bell, which began in 1969. In 2006 Lake Forest High School had to temporarily shut down their varsity football team due to allegations of the use of painkillers. Lake Forest forfeited their final three games for that season. Lake Forest leads the all-time series, just 20 to 19, but Milford has won 4 of the last 5, including a forfeit in 2006 and a 41-0 blowout on November 9, 2007 in the season finale. In 2008, starting only 4 seniors and 6 juniors, the very young spartan team improved to 3-7 and lost to Milford 28-14. Milford later made it to the state championship game. The Lake Forest Football team finished the 2009 season 7-3,in the annual Battle of the Bell the Spartans defeated rival Milford 26-0. Head Coach Freddie Johnson was named the Henlopen Conference Coach of the Year for the 2009 season. In 2010 the Lake Forest football team was crowned Southern Division champions. The Spartans finished 8-3, and suffered a one-point loss to Archmere in the state playoffs. Lake Forest Spartan senior Quadir Bryant was named the 2010 Delaware State Offensive Player of the Year. In 2011 and 2012 the Spartans finished 5-5, in 2013 the Spartans finished 6-4. The Spartans have extended their annual Battle of the Bell winning streak over rival Milford to 3 wins in a row. In 2014 the Lake Forest football team completed a perfect regular season 10-0, the second undefeated regular season in the school's history. The Spartans were crowned Southern Division Champs, and Head Coach Freddie Johnson was named the Henlopen Conference Coach of the Year for the 2014 football season. The Spartans dropped a tough first round loss in the state playoffs to Hodgson Vo-Tech 22-13. Hodgson Vo-tech went on to win the 2014 Division II State Championship 42-0 over the Laurel Bulldogs. Lake Forest Spartan senior John Flamer was awarded the 2014 Delaware State Defensive Player of the Year. The Spartans defeated Milford 40-13 in the Battle of the Bell.
Girls' basketball
Under the direction of first-year Head Coach Trenita Shields, the Lake Forest Spartans finished 16 - 4 and qualified for the DIAA State Tournament for the first time since 1992. The Lady Spartans won their first-round game versus the Seaford Blue-Jays. The Spartans lost the second round to Sanford, who went on to win the 2014 DIAA State Championship.
Wrestling
In 2013-14, under the direction of Head Coach Mike Hansen, the Lake Forest wrestling team qualified for the 2014 DIAA State Dual Meet Championships. The Spartans defeated DMA in the first round and lost to Milford Buccaneers in the semi-finals, who went on to win the 2014 Division ll State Championship. In 2014-15 the Spartans again qualified for the 2015 DIAA State Dual Meet Championships and defeated Caravel Academy in the first round. Lake Forest again made it to the semi-finals of the State Team Duals only to lose to the Milford Buccaneers for the second year in a row. Spartan, Brian Thomson won the 2014-15 Delaware State Championships at 170lbs and John Flamer placed 3rd at 220lbs
Softball
The Lake Forest softball team has improved over previous years and were 12-6 in the 2015 season. They are hoping to create a winning tradition for many years to come. The softball team is coached by Ashlie Tatman and is assisted by Cassie Butler. The softball team won a state championship under the guidance of coach Al Wood in 1979.
Cross country
Lake Forest has a successful cross country team, with a record of 7 wins and 4 losses in the 2007 fall season. Though their top runners graduated in 2008, the girls' team still had a strong freshman base. In 2009 the girls' cross country team claimed a division title. In 2014 the boys' and girls' cross country teams finished 7-4 and claimed the Southern division title under first-year Head Coach Eric Payne.
Track & field
Lake Forest has a track tradition that dates back to the 1980s and 1990s, when they won several division, conference, and state championships. Head Coach Freddie Johnson has the Lake Forest track team in contention for division, conference and state championships every year. The boys' and girls' teams both received southern division championship titles in the 2007, 2010, 2011, 2013, and 2015 seasons. The boys' team won the Keith S. Burgess Invitational in 2010, 2014, and 2015. The girls' team won the 2014 division Championship.
Girls' soccer
First-year head coach Pete Randazzo led the Lady Spartans to their first ever DIAA Division ll State Playoff appearance. The Spartans finished the regular season 10-4-1, Pete Randazzo was named 2014 Henlopen Conference Coach of the Year, and assistant coach Wayne Tiller was recognized as the Assistant Coach of the year for the Henlopen Conference.