The Danish striker was late for a flight from Newcastle Airport when he was caught by a Northumbria Police traffic officer on the A696 dual carriageway, which has a 70mph limit, last December.
Bendtner, who is on loan at Sunderland for a year from his parent club Arsenal, did not appear before Newcastle magistrates for the hearing.
The court was told the 24-year-old was in Denmark for "contractual obligations".
He was deemed to not be absent from court because he was legally represented at the hearing.
Sarah Robinson, prosecuting, said Bendtner was spotted driving his convertible Porsche 911 Turbo and he was measured to be driving at 103.6mph for 0.137miles at 10.53am on Saturday December 10.
Barry Warburton, defending, said: "I understand he was going to Newcastle Airport, he was slightly late for a flight and unfortunately he speeded.
"It was a Saturday morning, there was very little traffic on the road and weather conditions were fine."
Addressing the bench, he added: "Not withstanding the fact he is in Denmark, he has been absolutely no trouble to anybody. In my respectful submission, your public duty can be discharged by treating him with leniency."
The solicitor said his client had "substantial" disposable income and could pay the fine immediately with a credit card.
Chairman of the bench Edward Wardrobe imposed a 56-day driving ban, and fined the footballer £660, plus £30 costs and a £15 victim surcharge.
No penalty points were added to the three Bendtner has on his licence.
In 2009, his father Thomas said his son was "lucky" to escape with only cuts and bruises after crashing his Aston Martin on the way to training. A photograph of the written-off sports car showed it had been badly mangled.
He will appear before the same court in a week alongside Sunderland captain Lee Cattermole.
They were charged with criminal damage after a number of cars were attacked in Newcastle's Stowell Street in December.
Bendtner was engaged to Baroness Caroline Luel-Brockdorff, a wealthy member of the Danish royal family and the mother of his child. They split soon after the birth of their son in December 2010.
The self-confident striker is currently playing in a mask after suffering a broken nose. It has been customised to include his initials, the "52" shirt number and the Danish flag.
Bendtner was ineligible to play for Sunderland in their win against Arsenal in the FA Cup on Saturday and he was caught by TV cameras watching the game wearing a rakish trilby hat.