Sources close to the former couple tell us they split within the last few weeks, and it's unclear right now what led to the breakup.
Instantly, the two were constantly posting pics together all over both of their social media pages. Some of their greatest hits include flirty birthday posts and some fun TikTok dance vids.
It was also Cody who took care of Miley in November of last year when she underwent vocal cord surgery -- and in March, they got matching tattoos.
They were out together back in June when they grabbed coffee in Calabasas, and in early July they were jamming on TikTok together.
Cyrus has plenty to look forward to though, professionally at least ... her new single "Midnight Sky" is set to drop tonight.