The Evening News revealed last month that the Easter Road side were keen on the former Raith Rovers and Dundee United hitman as they looked to augment a strikeforce of Jason Cummings, James Keatings and Grant Holt with additional physicality.
The 6ft 2ins 28-year-old, who scored six goals for County in four Betfred Cup matches this summer, insisted earlier this week that he hadn’t had any contact from the Easter Road club, but late last night he was released from his contract in Dingwall to facilitate his move to Easter Road.
Graham said: “I am delighted to have joined Hibernian.
“I’ve been happy with my pre-season and start, and am looking forward to continuing this at Hibs.
“Everyone knows the size and stature of the club here. Promotion is the number one aim this season and I hope to be able to help achieve this.
Hibs head coach Neil Lennon said: “We’re very pleased to have signed Brian.
“He’s a goalscorer and will give us another option going forward when we’re trying to break teams down.
“We’ve started the season well and the additions of Brian and Andy (Shinnie) will further strengthen our squad.”
Graham has scored more than 100 career goals, including 17 for County since signing for the Dingwall side 13 months ago.