Ryan, who spent the second half of the past season on loan at Arsenal from Premier League rivals Brighton and Hove Albion, has been linked with a move to Celtic.
The Scottish giants are preparing an offer for the Australia international goalkeeper, according to Football Insider.
Arsenal are also reported to be keen on the 29-year-old, who is valued at 3-5 million.
Former Tottenham Hotspur and England international goalkeeper Robinson believes that Ryan would be a very good signing for Celtic.
Robinson told Football Insider: “I’d never thought about that but it would be the perfect fit. Fraser Forster went up there and did a great job but they have struggled in that department since he’s left.
“Mat Ryan was unlucky to lose his place at Brighton in my eyes. I think he still has a lot to give and I think he showed that in his handful of appearances at Arsenal last season.
“In my opinion, he is a top class goalkeeper. He would be a great signing for Celtic given his age, experience and ability.He would be a very stable presence between the sticks for them. I think he’s a great option for them.”