Lewis, who moved north of the border to Aberdeen in 2016, will aid the club in helping to "promote golf to people of all ages and abilities".
Dons skipper Lewis, a 12.5 handicapper, was delighted to be offered the role after becoming acquainted with the Hawkshill and Swailend courses. "It's great to be able to support a local golf course, and I love going there," he said. "I was a member at Newmachar last year, so I know the place and a lot of people who play there. It's a perfect fit. I love my golf, so to become an ambassador is something I am really pleased about and proud of."
He added: "I really enjoy the courses. Hawkshill is a bit more of a test, especially the way I play, which is not always the straightest of golf! Newmachar is a great club with a great set-up and I'm really pleased to be able to promote it and encourage as many people to get down there as possible."
Newmachar committee chairman Gordon Angus said: "Joe will be a familiar face to many, and we are delighted to have him on-board as club ambassador."