'She couldn't be happier!' Thandie Newton announces pregnancy as she walks the red carpet for her new movie at Toronto

PUBLISHED: 00:19, 9 September 2013 | UPDATED: 08:10, 9 September 2013

As she walked the red carpet with her husband Ol Parker at her side, it was clear Thandie Newton was excited.

And with little wonder - the actress, 40, is pregnant with her third child.

A spokeswoman for Thandie revealed the news as she appeared at the Toronto Film Festival premiere of her new movie Half Of A Yellow Sun.

Congratulations! Thandie Newton and her husband Ol Parker confirmed they were expecting their third child

'She couldn't be more happy,' a source told Us Weekly. 'You can barely tell she has a bump and she's been dressing different because of it.'

But the actress isn't showing just yet.

On Sunday, she wore a black and white dress which showed just the slightest bump at her waistline.

No baby bump: The 40-year-old actress showed no signs she was pregnant at the Toronto International Film Festival premiere of her movie Half of a Yellow Sun

The strategic design hided any hint of a baby bump. The Crash star paired her patterned frock a with bronze and balck clutch, chunky heels and her husband.

Ol let his wife shine, opting for a grey dress shirt and tie with black trousers and a jacket.

Thandie and her writer-director husband have been married for 15 years.

Holding hands: Chiwetel Ejiofor at the premiere of his movie Half of a Yellow Sun at the Toronto International Film Festival

Black and white: Anika Noni Rose stuns in form-fitting dress as the Toronto International Film Festival premiere of Half of a Yellow Sun

Shining bright: Chimamanda Ngozi Adichie wears a bright yellow dress to the premiere of Half of a Yellow Sun at the Toronto International Film Festival

Dapper duo: Executive producers Yewande Sadiku and Muhtar Bakare arrive at the Toronto International Film Festival Premiere of Half Of A Yellow Sun

The expectant couple are already parents to two daughters - Ripley, 12, and Nico, eight.

Half of a Yellow Sun, which is based on a novel by Nigerian author Chimamanda Ngozi Adichie, follows four people as they navigate the struggles in pre-republic Nigeria.

Chiwetel Ejiofor (12 Years a Slave) and Anika Noni Rose (The Good Wife), who star in the movie with Thandie, were also on hand for the premiere.

Four lives: Half of a Yellow Sun follows four people during pre-independent Nigeria

Based on a novel: Thandie plays Olanna in Half of a Yellow Sun, which is based on a book

Anika wore a curve hugging black and white horizontally patterned dress while Chiwetel donned a blue suit.

Chimamanda shined in a yellow peplum waist dress for the event.

Thandie and her co-star Anika were spotted at the Variety Studio at Holt Renfrew on Sunday as well.

Busy day: Anika and Thandie attended the Variety Studio at Holt Renfrew on Sunday at the Toronto International Film Festival

Both actresses dressed down for the event. Thandie wore a vertically striped shirt, cropped black pants and multicolored boots while Anika paired a black blazer with and off white top and jeans.

Felicity Jones (Like Crazy) and Mireille Enos (World War Z) also attended the Variety Studio event.