Well Society chairman Graham Barnstaple and colleague Brian McCafferty have both been made full directors of the club.
Motherwell chief executive Leeann Dempster told the club's official website: "In what has been a fairly difficult few days for Scottish football, we are really pleased to have some good news to report.
"We started the Well Society as the vehicle towards full fan ownership and have overcome many hurdles since 2011.
"Graham and Brian's appointment to the club board is another major milestone in our adventure and something that is really worth celebrating.
"They take full part in the direction of the club, including a say on all issues and have equal voting rights to other board members.
"We would encourage as many fans as possible to join the society and together we can continue the fantastic success we have enjoyed in recent years, both on and off the park."
McCafferty said: "This is a significant step towards reaching our ultimate goal of gaining a controlling interest in the club on behalf of the fans."
The society will assume majority control of the club once fans have raised enough money to provide long-term financial security.