But the 30-year-old Rosenborg player has appealed and has been released until a hearing at a higher court.
The incident took place in September, with the City Court of Copenhagen shown CCTV footage in which it appeared Bendtner struck the driver in the face.
The Denmark international admitted hitting the taxi driver but said it was because he felt threatened.
Bendtner said the driver threw a bottle or a can towards him and his girlfriend when they left without paying.
“We think that it’s not good for the club and not good for Nicklas, but he remains a player in the club. We are keeping him,” said Tove Moe Dyrhaug, the chief executive of Bendtner’s Norwegian club Rosenborg.
He had loan spells at Sunderland, Birmingham City and Juventus while at Arsenal before making a permanent move to German club Wolfsburg.
He moved back to England to join Championship side Nottingham Forest in September 2016 before joining Rosenborg in March 2017.