The 6ft 5 inch striker has been a target of Boro boss Darren Kelly for some time.
Simpson also played for Hartlepool United and signs subject to international clearance.
The striker, 20, reuinted with Kelly who had him during a very successful loan spell with Hyde United, which included a goal at the Flamingo Land Stadium.
Simpson had previously been linked with Premier League giants West Ham, before making a move to play for Championship club Preston.
He has most recently been playing his trade in Ireland with Cork City.
Boss Kelly said:
"I've kept in touch with Connor over the past couple of years and during the summer I was contacted by a few higher league clubs about his availability. He has been a huge target for me for quite some time and I'm absolutely delighted to bring him in. It would have been very easy for Connor to go higher on much bigger money, but I've had a good chat with him about the club and he is very excited about playing for us. I know what he is about, what he will bring to our team. He has a lot of strengths and I am looking forward to utilising them. He is a big, strong lad, who can hold the ball up, but he is also very quick. I can't wait to see him up front with the other excellent attacking options we have at the club."
Met Office Thunder Warning for Yorkshire Coast
Four Drug Arrests in Sleepy East Riding Village
Concern Over Yorkshire Coast Hospital Travelling Distances
Scarborough Showpiece Finishes in Style on Bank Holiday Monday
Fears Over North Yorkshire School Transport Rise
East Riding's Police Force Seek Newcomer
Unusual Bird Rescue in Scarborough
York & Scarborough NHS Trust Says Vote for NHS Heroes
Difficult Start Continues For Scarborough Cricketers
New Property Marking Kit Set To Protect North Yorkshire Farmers
Labour Win North Yorkshire Mayoral Contest
Tory Candidate Edges Home in Humberside Commissioner Race
