The Magpies are helping the lower division club towards repairing Plough Lane after flooding damage.
Graham Stacey, a member of the democratic supporters' organization that owns AFC Wimbledon, set up a Just Giving page for donations.
Both sides are meeting in the third round of the Carabao Cup, with the game taking place at Newcastle instead of Wimbledon’s stadium due to the issue.
Stacey said: "Thank you to supporters from the likes of Newcastle, Brighton, Arsenal, Colchester and Southampton who have all rallied round. Football really is, at its core, one huge extended family."
A Dons statement read: "Earlier, we postponed the Newcastle United game, and thanks to them and the EFL for their swift action and agreement to reverse the fixture.
"Supporters are likely to have seen images or footage circulating of the significant pitch damage at our stadium, following record levels of water at the nearby River Wandle overnight.
"It has been an immensely difficult day for club staff given the extent of the flooding, with related damage to our pitch and stadium. No doubt it’s been a difficult day for our supporters and volunteers, seeing the scenes online too."
