The collection, entitled My Hobby, is currently on display above a shop in George Street.
Hill told BBC Scotland that he had kept quiet about his pastime until recently.
"I have been painting in secret for about 20 years. Basically what I do is I watch TV all day for TV Burp then I go to the kitchen and I get a piece of wood and I start painting," he said.
"It is just a way of winding down really," he added. "People have said to me, 'Maybe you should have an exhibition', but I always kind of thought this was a little private thing I had going. It wasn't like I was going to sell them."
The presenter also admitted that, like his humour, the paintings are heavily influenced by surrealism.
"The works are from an ongoing series depicting a parallel universe where nature, celebrity and surrealism collide. There is horse on a surfboard, Bruce Forsyth, Britpop coconuts, a portrait of Cheryl Cole and a memorial to Honey the guinea pig," he explained.
"This will be the first time I've shown my art to the public in a 'proper' exhibition so I'm excited and nervous."
Hill is currently writing X Factor: The Musical with Steve Brown and admitted that he is also working on The Harry Hill Movie.
He recently completed a series of eight stand-up shows at Stand 3, also in Edinburgh. He is due to film a reunion special of The Harry Hill Show for Channel 4 next year.
My Hobby is on show at the Edinburgh Art Festival until September 2.