The singer has reportedly decided to give her relationship with the Australian actor another go after her parents Tish and Billy Ray called off their divorce.
An insider told Hollywood Life: "Miley is so thrilled at her parents reconciling, and it made her stop and think that Liam is someone special in her life.
"Their feelings for each other never stopped, and now that their schedules are better suited for each other, they have been able to work it out. Plus her parents trust Liam.
"They started talking more at the same time Miley's parents were mending things. They started getting back together around Valentine's Day and are now back on as boyfriend and girlfriend."
The news of the reconciliation comes after Miley revealed she is "not single".
During a recent interview on an Australian radio show ahead of her visit to the country next June, Cyrus said: "I don't want to cross out the Australian boys but I may or may not be single... I love Australian boys though obviously.
"Liam and I are very close, I'm not going to comment too much, but you guys don't have to worry about that... I'm definitely not coming to Australia single."
The pair were recently spotted out together in Los Angeles.