A top aide to City Councillor At-Large Ayanna Pressley is joining a national public affairs and communications firm. James Chisholm, Pressley’s chief of staff, will be heading up Resolute Consulting’s new Boston office as a vice president.

Resolute Consulting is based in Chicago, Pressley’s hometown, and founded in 2002. The company, which has worked with AT&T and Coca-Cola, also has offices in Atlanta, Detroit, Columbus and Washington, D.C.

Chisholm joined Pressley’s City Hall staff in Jan. 2010, after working on her first campaign. Chisholm left City Hall last week.

Pressley, a Dorchester resident, and Chisholm worked together in U.S. Sen. John Kerry’s office, where Pressley was a political director and Chisholm was a deputy press secretary. Chisholm has also written for ESPN.com and studied at Connecticut College.

“We are thrilled to expand into the northeast and welcome a person of James' caliber to the team,” Greg Goldner, Resolute Consulting founder and CEO, said in a statement. “James’ knowledge and experience will further enhance our ability to serve our growing client roster.”