Time Warner announced on Wednesday that 99% of votes cast were in approval of the merger. The New York City-based company said it expects the deal to close by year's end.
Shares of AT&T and Time Warner were mostly flat in after-hours trading on Wednesday.
"I'm pleased that the Company's shareholders have approved the proposal to combine with AT&T," said Time Warner CEO Jeff Bewkes in a statement. "By combining Time Warner's leading brands and video content with AT&T's distribution, we will accelerate our ability to innovate, develop and deliver the next generation of video services, making our content even more valuable to consumers and business partners."
The blockbuster deal is now likely to face an extensive regulatory review process, since a merger would create a powerhouse in global telecommunications, television and film.
President Donald Trump criticized the deal while on the campaign trail, saying he would oppose the merger because it would "consolidate too much power in the media industry."