Antonia Kidman shows off her trim bikini body as she hits the beach with her sons in Sydney

Her sister Nicole Kidman is known for her long and lean modelesque figure.

And on Thursday, Antonia Kidman proved good genes certainly run in the family as she turned heads during a beach outing in Sydney.

The 50-year-old mother-of-six showed off her incredibly toned and tanned figure in a black bikini as she soaked up the sun with her sons Alexander, eight, Nicholas, 10 and James, 18.

Soaking up the sun! Antonia Kidman, 50, showed off her trim bikini body as she hit the beach with her sons Nicholas, Alexander and James in Sydney on Thursday

Summer fun! The 50-year-old mother-of-six showed off her incredibly toned and tanned figure in a black bikini

Summer fun! The 50-year-old mother-of-six showed off her incredibly toned and tanned figure in a black bikini

Going makeup-free for the occasion, the beauty left her hair out while accessorising her look with a waterproof wrist watch.

Antonia was all smiles as she walked along the rocks after enjoying a dip in the water.

After her swim, the mother-of-six was spotted relaxing on the sand with Nicholas, Alexander and James.

The beauty left her hair out while accessorising her look with a waterproof wrist watch

She showed off her flawless complexion, going makeup free for the occasion

Natural beauty! Going makeup-free for the occasion, she left her hair out while accessorising her look with a waterproof wrist watch

Family fun! Antonia was all smiles as she watched her youngest son jump into the water

Family fun! Antonia was all smiles as she watched her youngest son jump into the water

The doting mother and her three sons sat under two beach umbrellas and chatted as they had a snack.

Before heading home, Antonia put on a short white dress and black hat and enjoyed a stroll along the sand.

The family were then seen carrying all their belonging as they walked to their car.

Making memories: Antonia soaked up the sun as she spent time with her son near the water

Making memories: Antonia soaked up the sun as she spent time with her son near the water

Enjoying a break: After enjoying a swim, the mother-of-six was then spotted relaxing on the sand with Nicholas, Alexander and James

Enjoying a break: After enjoying a swim, the mother-of-six was then spotted relaxing on the sand with Nicholas, Alexander and James

Break time! The doting mother and her three sons sat under two beach umbrellas and chatted as they had a snack

Break time! The doting mother and her three sons sat under two beach umbrellas and chatted as they had a snack

Stroll: Before heading home, Antonia put on a short white dress and black hat and enjoyed a stroll along the sand

Stroll: Before heading home, Antonia put on a short white dress and black hat and enjoyed a stroll along the sand

Antonia shares four children, daughters Lucia, Sybella and sons Hamish and James with her late ex-husband Angus, who she was married to until 2007.

Angus tragically died of a heart attack in 2015.

Antonia welcomed her youngest two children, Nicholas and Alexander with current husband Craig Marran.

Family: Antonia shares four children, daughters Lucia, Sybella as well as her sons Hamish and James with her late ex-husband Angus, who she was married to until 2007

Family: Antonia shares four children, daughters Lucia, Sybella as well as her sons Hamish and James with her late ex-husband Angus, who she was married to until 2007

Motherhood: Antonia welcomed her youngest two children, Nicholas and Alexander with current husband Craig Marran

Motherhood: Antonia welcomed her youngest two children, Nicholas and Alexander with current husband Craig Marran

Antonia is a known proponent of healthy eating and fitness.

The media personality previously told Nature and Health that she loves vegetables and salads and that she either runs or swims every morning. 

Meanwhile, Antonia enjoys a close relationship with her sister Nicole, 53, an Oscar-winning Hollywood star who is married to Keith Urban.

Going home: The family were then seen carrying all their belonging as they walked to their car to head back home

Going home: The family were then seen carrying all their belonging as they walked to their car to head back home

Antonia wore a white shirt and tiny denim shorts as she held her beach bag, towel and a newspaper

She tied her short brunette locks up and wore white sandals

Busy mum: Antonia wore a white shirt and tiny denim shorts as she held her beach bag, towel and a newspaper

In June last year, Antonia revealed she’s been thinking about adding to her family of six and is considering getting a dog.

She said in a column for 9Honey now that her family has relocated back to Australia and live in a house with a sizeable backyard – after almost a decade of living in Singapore –  the idea of getting a family pooch was on the cards.

She wrote that the love a dog owner has for their pet ‘seems so unconditional, solid and enormous and I don’t want to go through life without experiencing it’.

New family addition? In June, Antonia revealed that she's been thinking about adding to her family of six and is considering getting a dog

New family addition? In June, Antonia revealed that she’s been thinking about adding to her family of six and is considering getting a dog

'I don't want to go through life without experiencing it': She said her family has relocated back to Australia and live in a house with a sizeable backyard - after almost a decade of living in Singapore - the idea of getting a family pooch was on the cards

‘I don’t want to go through life without experiencing it’: She said her family has relocated back to Australia and live in a house with a sizeable backyard – after almost a decade of living in Singapore – the idea of getting a family pooch was on the cards