O'Donovan, 27, arrived on a short-term contract from Coventry in January and his six goals in 16 starts impressed manager Aidy Boothroyd enough to earn a longer deal.
Boothroyd told the club's official website: "There was considerable interest in Roy from a number of clubs from a higher level and we had to work hard to secure Roy's signature. But Roy feels settled with us and we are delighted we have been able to keep him.
"I thought he was terrific for us towards the end of the season and once he has got a full pre-season under his belt I think we will have a real player there."
- Sports & Recreation
- Aidy Boothroyd