Haaland and Bellingham were teammates at Borussia Dortmund, before Haaland moved to City this past summer.
Bellingham, whose own future is up in the air at Dortmund, has been a revelation for the Three Lions at the World Cup in Qatar.
"He's always really encouraging," Bellingham told BBC Sport.
"He messaged me before and after the first game just saying, 'good luck' and then he said 'well done'. He's a top guy."
The talented teenager added: "We speak every now and then to be fair.
“Normally when we're both playing it's more often, but it's normally silly stuff to be honest, just if he sees something that makes him laugh or if I see something that we've talked about before we'll send it to each other.
“But it's never like every day, checking up on each other, you know."