Doncaster have made forward Dany N'Guessan their sixth summer signing.
Tottenham have confirmed that Romanian defender Vlad Chiriches has completed a move to Napoli.
The 26-year-old centre-back is nearing his 200th appearance for County and replaced Paul Lawson as the most loyal servant among the playing staff when the midfielder left for Motherwell earlier this week.
Boyd formed a solid centre-back partnership with Grant Munro for the majority of the season to help County finish fifth in their debut Clydesdale Bank Premier League campaign.
Manager Derek Adams told the club's official website: "I am delighted Scott has decided to stay with us next season as he has been a valuable player over the past six years.
"He joined Ross County when we were in the Second Division and now has a collection of medals to his name."