Dortmund ascended to the top of the table following a 4-0 win over Eintracht Frankfurt on Saturday while nearest challengers Bayern Munich slipped to a 3-1 defeat at Mainz.
Bellingham, who has been touted for a big-money move this summer, opened the scoring for Edin Terzic's men.
With five games to go, Dortmund hold a one point lead over Bayern as the season enters a crunch stage.
Bellingham has already won the DFB-Pokal in his time at the Signal Iduna Park and is looking for the icing on the cake with Dortmund's first Bundesliga title since the 2011/2012 season.
"To be honest, it would mean everything. It would mean the world to me," he told Sky Sport Germany.
"I don't want to get ahead of myself and talk about it too much, to end up feeling like I've already won it, as there's five really tough games to come.
"But it would be massive, I would love more than anything to win the league with this club, after everything it's given me. I'll give absolutely everything to try and make that happen."
Bellingham has scored 11 goals in 39 appearances for Dortmund this season.
