The 56-year-old will join more than 100 other players at the World Snooker Academy in Sheffield in May, from which 12 players will be given places on the tour.
The four semi-finalists from each of three tournaments will be handed a place on the pro circuit for the next two seasons.
Knowles, who shot to fame in 1982 when he beat Steve Davis 10-1 in the first round of the World Championship and went on to win two ranking events in his 1980s prime, said: "The circuit is going in the right direction and the game is going world-wide. This is a great opportunity, especially with the two year tour card on offer.
"I know there are a lot of very good young players now but maybe I can still teach them a few tricks. Steve Davis and Jimmy White are still going strong on the main tour so I decided to give it a go."
Knowles, who owns a bar in Cumbria, insists that he is far better prepared for Q School this season than he was this time last year.
He said: "I played in Q School last year but I didn’t give myself enough time to practise because I had a lot of other work going on.
"That work is nearly finished now so I will have a lot more time to devote to playing snooker. I want to do it as a way of relaxing more than anything, but I want to give myself the chance to play in professional events."