The Team TotalEnergies rider crashed into fans at high speed while they were lined up on a cobblestone road on stage five between Lille and Arenberg.
Footage shows Oss being thrown off balance after clipping a fan before colliding with another, who leans out to film the race on a phone.
“Follow-up investigations revealed a fracture of a cervical vertebra that will require immobilization for a few weeks,” the team said in a statement read.
“Daniel Oss is therefore forced to leave the Tour de France… The whole team wishes you a speedy recovery Daniel.”
Several crashes, though not all serious, occurred during Wednesday’s Stage 5 as riders rode on cobblestones.
The Italian was able to somehow complete the stage despite the crash that also involved two other riders who fell behind him.
During last year’s race, a fan caused a serious accident after stepping in front of the race pack with a cardboard sign that appeared to display a message for the television cameras. The woman in question was subsequently identified and arrested by the authorities.
Slovenia’s Tadej Pogacar is now the current Tour leader after winning Stage 6.