The actor, who has daughters Rumer, 34, Scout, 31, and Tallulah, 29, with Willis posted a video of the entire Willis clan on Instagram singing Happy Birthday to the star - who recently confirmed he has dementia.
Moore, 60, was married to the Die Hard star from 1987–2000. Following their split, he married Emma Heming - and the pair have two daughters Mabel, 10, and Evelyn, eight.
The family were all seen singing to the star in the video posted on Sunday - Willis’ birthday - before presenting him with a candlelit apple pie.
Moore wrote: “Happy birthday, BW! So glad we could celebrate you today.
“Love you and love our family. Thank you to everyone for the love and warm wishes - we all feel them.”
Willis – known for his action roles but in particular for playing New York City detective John McClane in Die Hard – was confirmed to have been living with frontotemporal dementia (FTD) by his daughter, Rumer, on February 16.
Prior to this Willis – who starred in hit films including Pulp Fiction, Armageddon, Moonrise Kingdom, 12 Monkeys and Looper – had said he would be “stepping away” from his successful career after being diagnosed with aphasia, a condition affecting his cognitive abilities.
Also on Sunday, Heming, 44, held back tears as she explained on Instagram that she had been watching old videos of the Hollywood star for a birthday post.
She said watching old footage of her husband felt like “a knife in my heart” and admitted she had spent his birthday morning in tears.
In a video posted on Instagram on Sunday, Heming said: “So today is my husband’s birthday. I have started the morning by crying. As you can see by my swollen eyes and snotty nose, I just think it’s important you see all sides of this.
“I always get this message or people always tell me like, ‘Oh you’re so strong, I don’t know how you do it.’ I’m not given a choice. I wish I was. But I’m also raising two kids in this.
“So sometimes in our lives we have to put our big girl panties on and get to it. And that’s what I’m doing. But I do have times of sadness every day. Grief everyday. And I’m really feeling it today on his birthday.”
Bruce Willis - In pictures
Speaking about creating the birthday Instagram reel, she added: “So I worked on this reel that I’m posting for my husband’s birthday. I don’t know why I do that because the videos are like a knife in my heart.
“But as much as I do it for myself I do it for you. Because I know how much you love my husband and - don’t cry Emma - but it means so much to me so thank you.”
Heming later posted the montage of Willis with a backing track of Stevie Wonder’s classic song As.
She wrote in the caption: “He is pure love. He is so loved. And I’ll be loving him always. Happy Birthday my sweet.”