The rapper died at the age of 26 after an overdose, according to TMZ, and Chance has already taken to Twitter to heap praise on his good friend, describing Miller as ''one of the sweetest guys I ever knew''.
He wrote on the micro-blogging site: ''I dont know what to say Mac Miller took me on my second tour ever. But beyond helping me launch my career he was one of the sweetest guys I ever knew. Great man. I loved him for real. Im completely broken. God bless him. (sic)''
Fellow rapper Wiz Khalifa said on Twitter: ''Praying for Mac's family and that he rest easy (sic)''
Similarly, J Cole wrote: ''Rest In Peace to the great soul Mac Miller (sic)''
Meanwhile, Shawn Mendes said: ''Unreal. So sad. RIP Mac Miller [love hear emoji] (sic)''
Noah Cyrus posted a photograph of Miller and described him as an ''inspiration''.
She wrote on Twitter: ''im at a loss for words. we lost an inspiration to fans and many musicians. youre a musical icon forever. Rest in Peace Mac Miller [love heart emoji] (sic)''
Miller dated Ariana Grande for nearly two years, before they split in May.
The 25-year-old singer - who is now engaged to TV star Pete Davidson - is yet to make a public comment on the news, but is said to be devastated by Miller's death.
A source told 'Entertainment Tonight': ''Although the two ended their relationship, Ariana always shared a deep connection with Mac and wanted nothing but the best for him. Ariana is very upset.''
Another source said: ''Despite their split, Ariana had always been supportive of his sobriety.''
Meanwhile, Miller's family has issued a statement about his death.
It reads: ''Malcolm McCormick, known and adored by fans as Mac Miller, has tragically passed away at the age of 26. He was a bright light in this world for his family, friends and fans. Thank you for your prayers. Please respect our privacy. There are no further details as to the cause of his death at this time.''