The independent agency is headed by chief corporate counsel Iain Anderson and MD Jeremy Swan. It already has an office in Brussels, where four staff are based, as well as its 20-strong London headquarters.
By establishing a presence in Washington, Cicero hopes to tap into the ongoing global debate around the future of financial regulation.
The move is intended to provide European clients with better links to key policy-makers and regulators in the US.
Cicero also plans to tap into increased interest from US firms in EU regulatory and political developments.
Anderson said: 'Opening a Washington DC operation is the next logical step in Cicero Consulting's growth. We have ambitious plans to serve our emerging US client base as a result of the ongoing global regulatory policymaker debate in London, Brussels and Washington.'
Cicero becomes the second public affairs firm to set up in the US in recent months, after Portland's decision to open an office in New York last year.
Cicero's Washington operation will be based in the Willard Building on Pennsylvania Avenue and will be headed by John Rowland, currently an account manager at Cicero and vice-chairman of the APPC Young Consultants' Committee.
Anderson said there were plans to hire an undisclosed number of further staff to be based in Washington. Anderson will also spend a significant amount of time in Washington and New York, although he will remain based in London.
To reflect the changes, the agency will change its name to Cicero Consulting Inc, with Anderson becoming president of the enlarged operation.
Meanwhile, Cicero has boosted its London team with the recent appointment of Kieron Merrett as senior associate.
Merrett was previously senior researcher to John McFall, best known as the former chairman of the House of Commons Treasury select committee and who is set to take his seat in the House of Lords.