The veto came a day after the state Assembly passed the bill, with the state Senate had passing it earlier in the week on Monday.
Christie, who opposes same-sex marriage, had vowed “very swift action” once the bill reached his desk.
Returning the bill to the Legislature, Christie reaffirmed his view that voters should decide whether to change the definition of marriage in New Jersey.
Celebrities like Ryan Adams and Andy Cohen have joined voters and gay rights advocates in blasting Christie’s decision.
Singer-songwriter Adams posted on Twitter, saying “Dear Chris Christie, the world is moving on without you. Laterz gangsta.”