Haverford is a member of the historic Inter-Academic Athletic League, or Inter-Ac, formed in 1887 as the Inter-Academic Athletic Association. The Inter-Ac is the country's oldest inter-scholastic athletic conference and was expanded in 2013 to include girls' sports. The league consists of The Haverford School, The Agnes Irwin School, The Baldwin School, The Episcopal Academy, Germantown Academy, Malvern Preparatory School, The Academy of Notre Dame de Namur, Springside Chestnut Hill Academy, and William Penn Charter School.
Haverford fields 16 interscholastic sports. In 2016-17, the cross-country, lacrosse, squash, swimming, and tennis teams were Inter-Ac League Champions. Ice Hockey was the IHL Champion and squash won the MASA and National Championship. In the past decade, Haverford has won championships in cross-country, soccer, football, squash, hockey, lacrosse, baseball, tennis, crew, wrestling, and golf.
In 2017, the Fords won the Heyward Cup for overall excellence in athletic competition in the Inter-Ac League. This was the School's 17th cup win, more than any other Inter-Ac school.