The ninth season of the American fictional drama television series ER first aired on September 26, 2002, and concluded on May 15, 2003.

The death of Mark Greene continues to affect his colleagues while a grieving Corday has left Chicago for England.

Elsewhere Romano suffers a horrific injury which has consequences throughout the season, Weaver finds herself promoted, Abby's family troubles resurface, Pratt continues to get on the wrong side of his colleagues, and Kovač and Carter join a relief mission in Africa, setting up a continuing story thread for following seasons.

Over the course of this season, Romano suffers setbacks after losing his arm, Abby and Carter lean towards a relationship, Pratt has troubles in both his personal and professional life.

She was joined by new associate producers Erin Mitchell (for the entire season) and Shelagh O'Brien (after the mid-season break).

Wells was promoted to executive story editor mid-season but left the staff with the close of the season.

Returning directors were Félix Enríquez Alcalá, David Nutter, Nelson McCormick, TR Babu Subramaniam, and Alan J. Levi.

After weeks of professional and personal setbacks, Carter leaves the ER — and Abby — behind to join the equally troubled Kovač on a relief mission in the war-torn Congo.