Netflix Sets 15 October Premiere for The Diplomat Season 4, Releases Teaser

Netflix has dated Season 4 of The Diplomat for 15 October 2026, releasing a teaser trailer and first-look images on 17 August (Variety). Keri Russell and Rufus Sewell return; the new season picks up directly after Kate discovers Hal and President Grace plotting to steal a Russian nuclear torpedo. Russell holds an Emmy lead-actress nomination for every season.