In all grades girls and boys are encouraged to participate in the School’s athletic program which emphasizes activities promoting skill, leadership, sportsmanship, and team building. Students in grades three, four, and five develop and hone skills in an intramural basketball league. Students in grades five, six, seven, and eight play in interscholastic sports. City Day athletes compete with teams from other schools in basketball, soccer, and volleyball.

The School fields six basketball teams, (three girls and three boys), two volleyball teams, (one boys and one girls), and a co-ed soccer team.

Since 2012, four of the School’s basketball teams have competed in the Chicago Area Middle School (CAMS) League. In that time, the School has won eight first place trophies, seven second place trophies, and a third place trophy. The School added volleyball in 2014 to its CAMS League offerings: The boys and girls volleyball teams have won second and third place trophies in the CAMS League.