Andriy Yarmolenko put the visitors ahead in the first half, before Mark Noble scored the double with the last kick of the opening period.
Rapid Vienna have never really threatened to come back, and David Moyes’ side enter their final group stage game knowing that first place is already in place.
West Ham almost took the lead after just six minutes. Arthur Masuaku played a nice ball for the first time in the box, and Jarrod Bowen’s pushing effort rolled just off the far post.
Rapid Vienna held on and started to develop in the game, but a five-minute spell just before the break gave the Hammers complete control.
Nikola Vlasic worked the ball well on the left wing before straightening a cross at the far post, where Yarmolenko was on hand to score the opening goal.
And with the final half-time action, Yarmolenko was knocked down in the box, Noble being right on the spot for his debut Europa League goal.
Bowen and Tomas Soucek both had the chance to extend the lead in the second half, but were turned down by the goalkeeper.
David Moyes took the opportunity to pull out some of his key men in preparation for this weekend’s trip to face Man City, and debuted Sonny Perkins, the youngster having a well-saved shot with his first touch.
West Ham saw the rest of the game for a comfortable win, and that’s the job done in Europe for the Hammers until the last 16 in March.