"Throwing it WAY back... what a 'blur.' #TBT," the actor wrote on Instagram alongside a photo from the set of The Last Song, the 2010 film where the couple first got together.
Notably, a younger looking Hemsworth is shirtless while Cyrus is seen sporting her formerly curly and long brunette hair.
The film marks the beginning of Hemsworth and Cyrus' love affair as they were engaged two years later in 2012.
In 2013, the wedding was canceled and the pair went their separate ways until they rekindled their romance earlier this year with Cyrus being spotted wearing her engagement ring once again.