Jonathan Scott thanked Zooey Deschanel for "bringing joy back into his life".
The 'Property Brothers' star paid tribute to his 'New Girl' girlfriend as she celebrated her milestone 40th birthday with a loving message.
Posting a sweet tribute on Instagram, he shared: "Happy Birthday to the beautiful human who brought joy and laughter back into my life."
Zooey also marked her birthday with a post on her Instagram account.
In the post, surrounded by balloons, she wrote: "Today I am celebrating 40 years of being on this planet! Life is wonderful and I am so grateful for all the amazing people in mine. Thank you for all the birthday wishes, my heart is full. (sic)"
Jonathan recently explained how Zooey "brings out the best" in him.
He gushed: "[The romance has] been amazing. What [a] way to start off 2020 with a whole new path in life. People keep saying to me, like, 'Jonathan, you feel so alive.' I'm like, 'Was I a dud before? What happened?' I will admit she brings out the best in me and she makes me want to be the best version of myself."
The 'New Girl' star went public with her romance with Jonathan just one week after announced she and husband Jacob Pechenik - the father of her kids Elsie Otter, four, and Charlie Wolf, two - had split after four years of marriage.
And the new couple found it funny when fans were shocked to see them together.
Jonathan explained earlier this week: "I don't think it was expected.
"You know, what's really funny to me is, yeah, you see online and on social media, the internet is obsessed and keeps posting [about us], but the funniest thing is everyone's like, 'She's dating who?!'"