The player was taken into custody after two men were injured in an early morning incident on Sunday in Cardiff.
The 31-year-old was arrested after the alleged assault on Caroline Street at around 2.45am on Sunday.
A South Wales Police spokesman said: "A 31-year-old man has today been arrested on suspicion of assault and has been bailed pending further inquiries."
The police were unable to confirm the date Bellamy was bailed until.
A Cardiff spokesman said: "We are aware of the reported incident involving one of our players last weekend and feel it would be inappropriate to comment while an ongoing police investigation is under way."