Billy Joel marks eldest daughter's new milestone with adorable photos

Billy Joel is in a celebratory mood as his eldest daughter Alexa Ray Joel is 40 years old now.

The doting father marked his first born’s birthday by sharing two sweet photos on social media.

As Alexa turned another year older on Monday, December 29, the 76-year-old American singer-songwriter and pianist took to his Instagram to share new pictures of the father-daughter duo.

"Happy Birthday Alexa Ray Joel!" the Piano Man hitmaker captioned the snapshots, capturing him hugging Alexa in honour of the occasion.

In the images, Billy was sporting a casual black shirt and olive green baseball cap, while the birthday girl donned a floral sundress.

In addition to the father’s heartwarming gesture, Alexa received a birthday tribute from her aunt.

The Riverside Way singer's sister Sailor Brinkley Cook shared a video of her smiling and dancing in the living room in celebration, captioning the Instagram Story post "Birthday girl" with a red heart emoji.

The five-time Grammy winner shares Alexa with his second ex-wife Christie Brinkley.

Alongside the daughter, whom he welcomed in 1985, Billy is also a father to Della Rose Joel, born in 2015 and Remy Anne Joel born in 2017.

He shares his younger daughters with his fourth and current wife, Alexis Roderick.