Arroyo was elected to represent District 17 in 2005, which covers several South Bronx neighborhoods including Hunts Point and Longwood. Her resignation will take effect on Dec. 31.
Her term would have been up in 2017 if she had served it out in full, and a special election to replace her would likely occur in February.
Arroyo was reelected to the City Council in 2013 despite three of her campaign workers getting charged with forging almost 100 signatures on her primary ballot petitions, including Derek Jeter’s and Kate Moss’s.
"It has been a privilege to serve the people who live and work in the 17th Council District, the people of The Bronx, and of the great City of New York," Arroyo said in a statement. "It is an experience I will always cherish, and I am proud to say we’ve made the Bronx a better place.
"I must now dedicate my time and efforts to address pressing family needs," she continued.