A cam-action expanding standoff connector and related method are disclosed for mounting a circuit board. The standoff connector includes a body and a plurality of mounting members having interior longitudinally-extending camming portions for engagement by a cam. A cam is configured to be positioned within the mounting members in a first position in which the mounting members are not expanded against the interior of a mounting opening and in a second position in which the cam engages the camming portions to expand the plurality of mounting members against the interior of the mounting opening. Since the camming action is horizontal only (purely radial), practically no vertical forces are applied to the circuit board and a best-fit alignment between a circuit board and heatsink can be established and maintained.