The King County Prosecutor's Office says Joseph Michael Vaughn, Michael Lee Leatherwood and Arrik Livson Riechel are being held on suspicion of assault.
Vaughn is being held on $5,000 bail, and Riechel and Leatherwood are held on $25,000 bail.
The three were arrested after participants in an anti-capitalist march Thursday through downtown Seattle vandalized cars, confronted police officers and sparked minor street fires.
Violence has plagued May Day in Seattle during the past two years, with protesters challenging police and sometimes stealing the thunder of much larger daytime events calling for immigrant and worker rights. Last year, police arrested 18 people from a crowd that pelted them with rocks and bottles.