The couple - who tied the knot in 2006 - celebrated their wedding anniversary earlier this week and used their Instagram accounts to send touching messages of one another to mark the milestone.
Keith, 51, shared a photo of himself and the 'Big Little Lies' star and wrote: ''Thirteen years of magic, music, romance, wild adventures, and the ongoing discovery of pure love. Happy Anniversary Babygirl xxxx.''
The 52-year-old actress shared a different photo and a more brief message on her own account.
She simply wrote: ''...love. Happy Anniversary Baby.''
Nicole - who has 10-year-old Sunday and eight-year-old Faith with Keith, and 24-year-old Connor and 26-year-old Isabella with ex-husband Tom Cruise - recently praised Keith for being so supportive while she shot harrowing scenes for the second season of 'Big Little Lies', in which she plays Celeste Wright, whose abusive husband Perry (Alexander Skarsgard) was killed off at the end of series one.
She said: ''...And on season two, which I can't really talk about now. But, yeah.
''I have the most extraordinary partner in life.
''I will always say that about him.
''I'm one of the very fortunate women in the world to have had a wonderful father, and I have a wonderful husband, and I'm just very -- I love to be able to say that, because to talk about the good men that have influenced me and affected me.''
And the 'Hours' star doesn't need anything more in her life other than her career and her family.
She said: ''I love having my artistic path, and then my other passion is my family. That's probably all I need in my life.
''Other people are off doing things like having a girls' weekend. I don't have that because I go home. I want to be with my children and my husband. I will sort of get lost in a character or whatever I'm doing, but I'm constantly working to keep that balance.''
Ahead of their upcoming tour, and prior to the release of their long awaited album, Smoke Fairies played a great warm-up gig at Elsewhere in Margate.
Country music has long been associated as a storytelling journey, but the evolution of the...
After having a music career that spanned five decades and saw the release of over...