Huy Trong Long, 40, of Jersey City, N.J., committed the crimes over a five-month period in 2008, police said.
He robbed one bank in Greenwich and another in Westport in January 2008, and a bank in New Canaan in April 2008, according to the U.S. Attorney's Office. The six other robberies happened in New Jersey.
Luong was arrested after an attempted robbery in Chatham, N.J. After the arrest, police found a black wig, a black Dolce & Gabbana hat, a women's make-up kit and a black jacket in his getaway min-van, according to a police complaint.
As part of the plea agreement reached Tuesday, Luong will face 70 to 87 months in prison when he's sentenced in July.
He must also pay $39,000 back in money he stole, plus any additional fines.