Olivia Newton-John has posthumously released a duet with Dolly Parton singing the country music star's hit, Jolene.

Newton-John died in August last year aged 73 at her ranch in southern California surrounded by family and friends.

The duet has been released alongside a video of the duo singing the song, first recorded by Parton in 1973 and covered by Newton-John in 1976.

In the video, Newton-John says, "I am excited, I have always wanted to sing with Dolly".

Newton-John won multiple Grammy awards over a five-decade-long career and was well known for her role as Sandy in the film Grease.

Parton shared the video on her Instagram page with the caption "I love you, and thank you for shining your light on us".

Parton said the pair had stayed close throughout the years and she was proud to be singing with her. 

“I am so excited to be working with Olivia Newton-John, one of my favourites of all time,” Parton said. 

Newton-John's daughter, Chloe Lattanzi, paid tribute to her mother on Instagram. 

"It is my honour and my privilege to be your baby, and to continue your legacy of love, light, generosity and most of all … humour!" she said. 

"Half of my heart is missing, but I know you're holding it for me. Waiting to give it to me when we meet again.

"Everyday I aim to make you proud. You told me, 'just be wonderful you' so I'll do [my] best."