Of the 8,525 votes cast, 99% of WGA members voted in favor, union leaders said in a statement to members.
The term of the new agreement runs through May 1, 2026.
"Through solidarity and determination, we have ratified a contract with meaningful gains and protections for writers in every sector of our combined membership," WGA West President Meredith Stiehm said. "Together we were able to accomplish what many said was impossible only six months ago."
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The announcement comes about two weeks after the WGA strike came to an end. Writers had been on strike for nearly five months.
Meanwhile, negotiations continue between the studios and the actors union, SAG-AFTRA. Actors have been on the picket lines since mid-July.
WGA East president Lisa Takeuchi Cullen urged the Alliance of Motion Picture and Television Producers to come to a fair agreement with striking actors.
"Now it's time for the AMPTP to put the rest of the town back to work by negotiating a fair contract with our SAG-AFTRA siblings, who have supported writers throughout our negotiations," Cullen said. "Until the studios make a deal that addresses the needs of performers, WGA members will be on the picket lines, walking side-by-side with SAG-AFTRA in solidarity."
City News Service contributed to this report.