Cowell has been absent from the live shows during his recovery. When viewers first noticed he was missing, NBC described the reason as a non-emergency medical procedure. The network’s explanation of his absence did not announce a date for his return.

Reports have described the procedure as back surgery. Cowell injured his back in a 2020 electric bike accident, but viewers should be careful about drawing their own conclusions from that history. No public update cited here establishes a new diagnosis or says that an emergency caused him to miss the finale.
The immediate effect is straightforward: Cowell will not be at the judges’ table for the last two broadcasts of the season. NBC’s finale guide sets out the schedule for the concluding performances and results.
Who is replacing Simon Cowell?
KSI is joining the finale as a guest judge. The British entertainer and content creator will sit with returning judges Howie Mandel, Sofía Vergara and Mel B. His appearance gives the finale a full panel, though it also changes the familiar dynamic between Cowell and the other judges.
KSI is the latest guest to fill Cowell’s seat during the live rounds. Kenan Thompson stepped in earlier in the season, and former judge Heidi Klum returned for a quarterfinals episode. Their appearances allowed the competition to continue while Cowell was away.
For the finalists, a guest judge brings a fresh reaction to performances they have spent weeks developing. For viewers, KSI’s presence is one of the finale’s most visible changes. It does not change the central question of the night: which act will win the audience’s support?
Does Cowell’s absence change the winner?
Cowell’s absence changes who comments on the acts from the judges’ table. It does not mean a winner has been chosen in advance. The finalists still perform, viewers have the opportunity to support their preferred acts, and the results are revealed in the concluding broadcast. NBC’s guide to the Season 21 finale provides the event details.
Cowell’s opinions are a recognizable part of AGT, so his absence will be noticeable. Still, the finale gives each act a chance to make its final impression on the audience. That matters more to the outcome than speculation about what Cowell might have said from his seat.
When is the America’s Got Talent Season 21 finale?
The two-night finale is scheduled for Tuesday, September 22, and Wednesday, September 23, 2026, on NBC. Viewers who miss the live broadcasts can check Peacock’s September streaming schedule for availability.
Cowell’s return date has not been confirmed in the sources cited here. Until he or the show provides a further update, the verified news is limited to his continuing absence, his recovery and KSI’s place on the finale panel.