Toussaint, a New Orleans music legend, died in 2015 of a heart attack while he was touring in Madrid.
Brossett introduced the ordinance last month to rename the boulevard after Toussaint instead of the Confederate general, saying in a news release "it's well beyond time to make this change."
"The City of New Orleans should prioritize celebrating our culture bearers, our diversity, and everything that makes our City special, not those who worked to tear us apart and represent a horrible history of racism that we are still dealing with today," Brossett said then in a statement.
"Allen Toussaint is a New Orleans native and world-renowned musician. He represents the very best of our city, and I am proud to take this step toward honoring his legacy," Brossett added.
The move follows similar efforts across the country in recent years, that have seen symbols of the Confederacy -- including names, busts and statues -- removed and replaced amid a nationwide reckoning with racism prompted by the killing of George Floyd.
Among the changes last year were a Florida school board voting to rename six schools named after Confederate leaders and Virginia removing a statue of Lee, which was the last Confederate statue that remained along Richmond's historic Monument Avenue.
Following news of the New Orleans city council vote, Louisiana state health officer Joseph Kanter wrote of Toussaint, "he was the best."
"Every important piece of New Orleans music the past half century ran through Allen Toussaint," Kanter wrote on Twitter. "No one is more deserving than him. And he was just the kindest man you'd ever meet. I had the pleasure of meeting him once and will never forget it."
The name change will take effect for the boulevard, which stretches through the northern part of New Orleans, on February 1, CNN affiliate WDSU reported.