Grande, 25, posted a black and white photograph of Miller who died on Friday aged only 26 from a suspected overdose.
Interestingly, she posted no words about Miller after previously turning off her comments section after being trolled following his death on Friday.
And the photograph gained over 2.3 million 'likes' from her fans as a mark of respect to Miller.
The couple had been friends before becoming romantically involved in 2016.
The pair split In after she became sick of his issues with drugs.
However, she remained supportive by reaching out to him via Twitter following his arrest for DUI just after their split.
She tweeted: "Pls take care of yourself" - Grande is now engaged to comic Pete Davisdon.
Police are still investigating the circumstances surrounding Miller's death while his autopsy was deferred pending toxicology results.
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