The 25-year-old British singer said Monday on SiriusXM's Radio Andy that he recently "cleared the air" with Malik following the 24-year-old star's departure from the boy band.
"We got back in touch with each other and kind of cleared the air and talked everything through," Tomlinson told host Andy Cohen. "So we're mates again, I suppose."
"Like anything like that, it takes time. But it was nice that we had an opportunity to clear the air and be adults about it," he added.
Tomlinson and Malik clashed on Twitter in 2015 after Malik quit One Direction after nearly five years with the group. Tomlinson told SiriusXM in January that he and Malik have improved their relationship since.
"It's a strange feeling, but it's nice," the star said of hearing Malik's solo music. "I think we've gotten to a point now where you can just really be happy for each other. Things have happened in the past, of course ... [but] it's great."
"His first song [Pillowtalk] was an absolute smash, and that's a great song. So yeah, it's nice," he added.
Tomlinson released his first solo single, Back to You, in July, nearly 19 months after he and the remaining members of One Direction started an indefinite hiatus. The singer told fans he's "really proud" of the song's music video, which was filmed in his hometown of Doncaster, England.