The 38-year-old musician dedicated a sweet post to Diaz on Instagram to celebrate her 45th birthday Wednesday.
"Happy Birthday to my Beautiful Wife," Madden captioned the picture, which shows him laughing with the Charlie's Angels star on a boat ride.
"I feel like I am the LUCKIEST guy ALIVE," he gushed. "I don't think anyone could ever know the Depth, Kindness, and Compassion that I get to experience everyday thanks to My One and Only- You got me til the end baby."
Diaz also received birthday wishes from friend and fellow actress Gwyneth Paltrow.
"Happy birthday @camerondiaz," the 44-year-old star wrote. "Your wisdom, humor, loyalty, cooking skills, guffaws and ice cubes in rose get me through my life. I adore you with all my [heart] (And yes, we are wearing bibs in this picture)."
Madden and Diaz married at their home in Beverly Hills in January 2015. Diaz opened up about her relationship with the musician while attending Paltrow's "In Goop Health" conference in June.
"He's just my partner in life, in everything. I've never had anyone who supported me so much and gave me so much courage to by myself and really explore myself," the actress said, according to People. "I look at him every day and he inspires me. I feel so lucky."
"[We] are totally two peas in a pod," she added. "We're both just weird enough for each other. He's my perfect little weirdo and I'm his perfect little weirdo."
Diaz last appeared in a 2014 remake of Annie.