Moyes was only appointed as Slaven Bilic's replacement in November, but the club have today confirmed that the Scot has left the London Stadium, meaning the search for a new boss is well and truly on.
Earlier this week, The Mirror reported that West Ham had held face-to-face talks with Shakhtar Donetsk boss Paulo Fonseca, but their hopes of landing him may already be over.
Portuguese newspaper O Jogo report that Fonseca has snubbed West Ham and has instead decided to stay in Ukraine and renew his deal with Shakhtar.
Fonseca, 45, won the Ukrainian domestic double last season and is set for a second straight league title this season, having impressed with his attractive brand of football.
The former Porto boss is now one of the most wanted managers in Europe, and West Ham were hoping to land a real coup with his signature, but it seems that they will have to go back to the drawing board with Fonseca preferring a stay with Shakhtar.