Heidi Gardner left "Saturday Night Live" after eight seasons because her contract was not renewed as part of a major cast shake-up for Season 51. Sources indicate it was not her personal decision to leave, but rather a production choice to refresh the cast. Gardner was the longest-serving female cast member and well-regarded for her versatile comedic performances, including notable characters on "Weekend Update." Despite her popularity, the show's executive producer Lorne Michaels decided it was "time for a new cast," leading to her and several other cast members' departures. Gardner herself had spoken of "sketch fatigue" earlier in 2025, hinting at challenges with the demanding schedule, but did not publicly comment on the exit at the time it was announced. This transition was part of a broader roster change ahead of the show's 51st season starting in October 2025.