Carroll has gone on loan for the Season with an option to buy next Summer.
The big Geordie was not wanted by Anfield Supremo, Brendan Rodgers who is hoping to add either Clint Dempsey, Daniel Sturridge or An Other.
"It's great to be here at West Ham and all signed up - I just can't wait to get started now," Carroll said. "I want to be playing games and obviously hoping to score some goals. I know the manager well and some of the lads, so it is nice for me to come to a place where I know people.
"I'm hoping to add a lot of goals and create a few chances. I know Sam from Newcastle and he was a massive reason for me coming. When I worked with him at Newcastle it was great so it was a no-brainer really."
Best of luck at West Ham Andy.