Eighty-six percent of the AFTRA ballots submitted were in favor of the merger, while 82 percent of SAG ballots endorsed the merger.
"The merger of SAG and AFTRA is approved," SAG President Ken Howard almost yelled.
"In a single day our future has become bright," he added.
The endorsement of a plan to bring the two guilds under one roof ends a two-year process that riled a small but vocal faction of union members.
Opponents of the merger launched protests in front of SAG's offices, took to Facebook and Twitter to vent their displeasure and launched an unsuccessful courtroom challenge to block a vote.
Proponents of the merger claim that by bringing the two unions together, SAG and AFTRA will strengthen their bargaining leverage with studios and other media companies.
Those in the opposition counter that merging the unions will have a dangerous impact on union members' pension and health benefits.
The merger needed the approval of 60 percent of the voters of both unions, something that eluded SAG and AFTRA when they tried to pull off a similar marriage in 2003.
In a devastating setback to opponents of the proposal, federal judge James Otero on Wednesday rejected a lawsuit that would have blocked a vote on the plan to join the unions.
Over 60 SAG members, including such household names as Martin Sheen and Ed Harris, had signed on to the lawsuit, which asked the court to require the union to perform a study on the effects that a merger will have on benefits.
Otero said there was insufficient evidence SAG had violated labor laws and that the planned merger should be decided by the membership.
(Editing By Bob Tourtellotte)