On Friday, Miller died of an apparent drug overdose in his home.
She made the wordless post right after her manager Scooter Braun wrote of Miller on Instagram, "Always a kind heart". He was reportedly found unresponsive and was pronounced dead at the scene upon the arrival of emergency officials.
Grande, who quickly became engaged to comedian Pete Davidson after splitting with Miller, did not immediately comment on the rapper's death but blocked comments on her Instagram page after a slew of critical remarks.
It's a burden that no one should have to shoulder - and given the simple fact that men are typically slower to speak about their problems, it's one that disproportionately falls on women.
The couple had dated for two years until parting ways in May, shortly before Miller was arrested for driving under the influence (DUI) and hit and run in Los Angeles. "At this time, an autopsy is pending and a cause of death has not been determined".
Mac Miller, whose real name is Malcolm James McCormick, had struggled with substance abuse in the past.
We're thinking of Mac's loved ones at this tragic time. They split up in the spring of this year, but the singer said she remained on good terms with her ex. I respect, and I adore him endlessly, and I'm grateful to have him in my life in whatever form, at all times, regardless of how our relationship may change or what the universe holds for us!
Another collab soon followed suit when Ari guested on Mac's song My Favourite Part that same year.
"A lot of times in my life I've put this pressure to hold myself to the standard of whatever I thought I was supposed to be, or how I was supposed to be perceived", he told the NY magazine's Vulture website. He loved everyone. I grew up listening to his music, and he inspired me.