“Bedford are a big, traditional club and I’m very fortunate to have this opportunity,” Cruse told the Blues website.
“It’s a really exciting challenge for me as I begin my coaching career, in a league that’s highly competitive.
“I’m a massive advocate of the Championship, it’s a great place to help talent grow, and I’m eager to put my stamp on things to aid that.”
Northampton play their final regular-season game at home to Bath on Saturday before embarking on the play-offs as they look to win a first title since 2014.
Bedford are currently fourth in the Championship and end their campaign away to Ealing Trailfinders on 25 May.
