The Limerick man’s one-year contract at the Brandywell had expired.
The winger made 35 appearances in all this season – 18 of those from the bench – and although he didn’t score competitively for City, he led the way in ‘assists’ with seven.
Manager Ruaidhri Higgins said: “On behalf of everyone at Derry City I want to thank Will for his contribution this season and wish him well for the future.”