Martin told the official Posh website: "The ambition of the chairman and the management team is brilliant and I see this move as a new challenge.
"I wanted to play at a higher level and further my career."
His new boss Darren Fergusson was delighted with his capture.
"He's a very consistent player and is flexible," said Darren
"His main position is right-back which is what we've brought him in to do but he can play midfield and centre-half."
He added: "He never missed a game last season, was Wycombe's best player and I'm really pleased to get him."
Wycombe will receive compensation because martin is under 24. If a fee cannot be agreed it will be settled by tribunal.