Members of Operation Pike, a joint operation set up in the wake of the damaging blaze on December 30, made the arrest in the Canberra suburb of Parkes on Thursday.
Police have charged a 30-year-old man with aiding or abetting arson of a building, defacing public property, assaulting frontline service workers and resisting a territory public official.
A 38-year-old man was also charged with assaulting a frontline service worker, obstructing a public official and breaching bail conditions.
Both men are set to face the ACT Magistrates Court on Friday morning.
It comes after ACT police arrested two men and a woman at Parliament House on Thursday following protests outside the building.
The trio were charged with breaching the peace, after protests attempted to enter parliament.
A police official said capsicum spray was used during the protest to control the group.
Social media footage posted by an anti-vaccination group showed protesters engaging with a line of police outside Parliament House.
The group has been involved in a number of protests this week including outside the prime minister's official Canberra residence.Â