The 27-year-old was an unmitigated success during a short spell at Fir Park last year and helped the club secure third spot in the table.
Despite receiving a number of offers to remain south of the border this summer, the utility player has opted to return to his homeland.
"I have spoken to Bob and he's agreed to sign on again for next season," Well boss Mark McGhee told the Daily Express.
"It's a big boost for everybody at the club.
"Once Bob gets a full pre-season under his belt he will prove to be a very important player for us.
"Bob offers us something different in the midfield and that is why we did everything we could to try and keep him."