The 33-year-old joins the Spiders after leaving Falkirk before the transfer window closed. He can also count Rangers, Kilmarnock, Partick Thistle and Hibernian among his former clubs.
Manager Ray McKinnon told the club website: "I think any club that wants to be successful has to have two extremely good goalkeepers and we now have that. Cammy is a top goalkeeper who I worked with at Dundee United and Falkirk and it’s excellent to have him at the club.”
