Mark Sahady, 46, and Suzanne Ianni, 59, both from Massachusetts, were arrested without incident at their respective homes on Tuesday, according to the FBI.
The pair have been accused of breaching the US Capitol on 6 January alongside a mob of pro-Trump supporters, as Congress attempted to confirm President-elect Joe Biden’s election victory.
Five people died and several more were injured in the riots, as House representatives barricaded themselves in offices to hide from the rioters.
Ms Ianni, who also serves as a Natick Town Meeting member, declined to comment to the FBI about whether she entered the US Capitol during the riots.
Both Mr Sahady and Ms Ianni were identified by photos posted to social media by the group Super Happy Fun America, who organised the “Straight Pride Parade” in Boston in 2019.
The FBI said that both of them are members of the group that claims to be an advocate for the “straight community” and whose motto is: “It's Great to be Straight.”
Ms Ianni is believed to be just a member of the group, while Mr Sahady serves as the vice president of the organisation.
The FBI also believes that Ms Ianni organised 11 buses to transport around 300 people to the riots on 6 January.
A day earlier, on 5 January, an account linked to the group posted a photo onto Twitter of members smiling, which was captioned: “Bus 1 of 11 coming to DC. See you there.”
Bus 1 of 11 coming to Washington DC. See you there! pic.twitter.com/66ktWpwZKL
— SuperHappyFunAmerica (@SuperHappyFunA) January 6, 2021
Ms Ianni was identified as being the woman in the left of the picture, while Mr Sahady is the man in the grey shirt standing next to her, according to CBS Boston.
Both Mr Sahady and Ms Ianni are scheduled to make their first appearance in US District Court in Boston on Tuesday.