Luke Grimes is to be a father for the first time.

The 'Yellowstone' actor's wife Bianca Rodrigues Grimes - who he married in November 2018 - has revealed she is expecting her first baby with the 40-year-old star and "can't wait" to meet the tot.

Bianca shared a photo on Instagram which featured a silhouette of herself posing for a mirror selfie with her bump on display and captioned the post: "Can't wait to meet you little one [heart emoji]."

Her husband has yet to comment on the happy news, and it is not known when the pair are due to welcome their baby into the world, or if they know whether they are expecting a boy or a girl.

Luke previously pledged to be with the Brazilian beauty "forever" and praised the model as a "real angel".

He told USA Today newspaper last year: "I'm a very married person and I love my wife to death. We'll be together forever.

"There's no way I earn it. I do my best. But I'm a flawed big ol' weird-a** man. She's the real angel here."

The 'Happiness for Beginners' actor also revealed classic NBC sitcom 'The Office' had been vital for their relationship because the programme had helped Bianca to learn English.

He told People magazine: "She moved to the States without knowing a word of English.

"And when I met her, she had only lived here for two years, but she spoke beautiful, fluent English. I was like, 'How did you learn it so fast?' And she said, 'I watched The Office with subtitles.' "