The Israeli international sealed a season-long deal at Upton Park in the dying minutes of transfer deadline day, and is pleased to be back at his old stomping ground.
"Thank you very much to everyone who has welcomed me back," he told West Ham's official website.
"I'm delighted to be here because I've been here before and this is a great club and I just cannot wait to start playing here again."
Benayoun is one of ten players snapped up by the Hammers, with Andy Carroll, Matt Jarvis, Alou Diarra, Modibo Maiga, James Collins, George McCartney, Mohamed Diame, Jussi Jaaskelainen and Stephen Henderson all joining Sam Allardyce's team.
"I think the deal went through about one minute before the deadline! We had a long day because I had conversations with a lot of teams during the transfer window and a few of them made offers to me.
"West Ham actually came in during the last few hours of the transfer window and, when they did, we tried to seal the deal and I was delighted when we did it.
"We have got a lot of quality in the team and a great manager, so it should be easy for me to fit in."
West Ham defeated Fulham 3-0 at Upton Park in yesterday's Premier League clash.