Fianna Fáil Councillor Mike Crowe said the mass gathering on Saturday night "doesn't portray Galway in a positive light."
An illegal bare-knuckle boxing match at the popular city centre square attracted a large crowd to the area. Footage of the incident was shared on social media over the weekend showing a large crowd with no social distancing being observed.
Eyre Square became the scene of another mass gathering following the conclusion of the Euro 2020 final on Sunday night as football fans swarmed on the area.
Speaking to local radio, Cllr Crowe stressed that Eyre Square "is a public park and is not a centre for such activities."
The councillor added that he was "disappointed to see such scenes at a time when hospitality is under such great pressure with many local businesses trying to operate in their outdoor spaces."