A man was wounded in the incident in Derry on Wednesday night.
The victim, who was in his 30s, was taken to Altnagelvin Hospital where he was treated for shotgun wounds to his hand - he was discharged a short time later.
It is reported that a fight broke out among guests who had arrived from all over Ireland to attend the wedding reception at Rafters Restaurant on the Northland Road.
The brawl then spilled out into the car park where the shooting happened shortly after 8.30pm.
It is understood the man arrested was not from the city and was stopped by Garda in Manorcunningham an hour after they were alerted by their colleagues in Derry.