It follows a dismal T20 World Cup for the West Indies, where they failed to reach the tournament's Super 12 stage in Australia following defeats against Scotland and Ireland.
Cricket West Indies said that Simmons' final assignment will be the two-Test series against Australia from November 30 to December 12.
"I acknowledge that it's not just the team that is hurting, but the proud nations we represent as well," Simmons said in a statement on windiescricket.com.
"It's disappointing and heart-wrenching, but we just didn't turn up. We weren't good enough, and we now have to watch a tournament play out without our involvement.
"It's unfathomable, and for that I deeply apologise to our fans and followers."