The South Iowa Cedar League is a high school athletic conference in south central and southeastern Iowa.

A 9-team league from the 1960s, the conference expanded to 12 teams in 1996, then dropped to 11 members when Williamsburg joined the Eastern Iowa Hawkeye Conference in 2000.

Boys' sports are administered through the Iowa High School Athletic Association, and girls' sports are administered through the Iowa Girls High School Athletic Union.

Football is played by districts based on their enrollment classification and geography, instead of by conference.

The conference offers the following sports: Although the member schools field junior varsity teams (for freshman and sophomore athletes) in many of the above-mentioned sports, conference championships are determined at varsity level only.