Suozzi lost a bid for a third term last fall to Republican Edward Mangano.
He was hired Monday as an adviser for the company's new high school sports venture, called MSG Varsity. The channel and an accompanying Web site cover high school athletics in the New York metropolitan area.
Suozzi lost a 2006 bid for the Democratic nomination for governor. Both he and Cablevision declined to reveal the length of his contract or the amount he is being paid.
Suozzi is both a lawyer and accountant. He has left open the possibility of running for public office again, but he says it would only be on the state or federal level.