Chandler Catanzaro nailed a 43-yard field goal as time expired to win it, moments after missing a 32-yarder on the previous possession.
The Tigers (9-1, 7-1 ACC) earned their second trip to the ACC title game in three years despite committing three turnovers and losing star wideout Sammy Watkins and left tackle Phillip Price to second-half injuries.
Wake Forest (5-5, 4-3), which erupted for 21 third-quarter points in less than five minutes, lost its third straight.
The Demon Deacons had a chance to go up 10 with under nine minutes left, but Jimmy Newman missed his second field goal, a 32-yarder. The Tigers promptly tied it on Tajh Boyd’s 10-yard strike to Jaron Brown.
Clemson’s Andre Ellington, returning from an ankle injury, ran for two touchdowns to give the Tigers a 14-7 halftime lead.
In the third, the Demon Deacons got a 50-yard punt return for a touchdown from Michael Campanaro.