Inside Delta Goodrem's secret wild 40th birthday bash as singer stuns in a sheer black designer dress

 Delta Goodrem turned 40 earlier this month. 

And the Born To Try hitmaker held a secret celebration for her milestone birthday.

Former Home And Away star Mia Morrissey was one of the few guests who posted a glimpse into the celebration to Instagram on Wednesday.

In sweet pictures from the birthday bash, Delta is all smiles as she holds a decorative '40' champagne flute.

For the big occasion, Delta stunned in a sheer black gown with flower detail and wore her hair up in a chic updo.

The actress also shared an image of the dancefloor, with Mia seen having a boogie with Delta's fiancé and bandmate Matthew Copley.

Delta Goodrem held a secret celebration for her 40th birthday this month 

In the caption Mia wrote, 'Had the MOST fun possible celebrating the birth of this wonderful, marvelous, drop dead gorgeous lady and all the joy, strength, power and inspiration she has brought not just me but everyone who has ever been blessed by her presence.

'I am so utterly overjoyed to call you family. I am endlessly grateful for you and all your magic my girl! Love you!'

Another post shared by Nine journalist Airlie Walsh gave a glimpse of the backyard vibe of the celebration.

Home And Away star Mia Morrissey shared an image of the dancefloor, and Mia can be seen having a boogie with Delta's fiancé and bandmate Matthew Copley.

Another post shared by Nine journalist Airlie Walsh (pictured right) gave a glimpse of the backyard vibe of the celebration..

In a black and white photo,  Airlie posed with Delta for a selfie.

In the background were several sets of outdoor furniture with sun shades as well as outdoor dining in another photo.

Airlie wrote in the caption: 'Celebrating our darling Delta Goodrem. Your light is unmatched. Happy milestone birthday!'

Delta herself later replied in the comments, saying, 'Thank you so much my beautiful friend.'

The former Neighbours star recently revealed she is excited for the next decade of her life.

'I’m so excited for a new chapter in my forties,' Delta told New Idea earlier this month.

'I’m going into my best moments yet, at this moment, right now,' she told the publication.

Last year, Delta went on tour around the world and starred in the Netflix film, Love Is In the Air.

'I’m most proud of where I am at right now. I’m in this moment in my life, that I still feel inspired and excited and grateful,' she remarked. 

'And I’m really proud to be doing what I love all these years later and be doing it better than I ever have.

'I think things just get better and better as you sort of, gain more knowledge of life, and continue to grow and learn.'