The 33-year-old singer and 42-year-old actor marked the occasion with a tropical getaway to Mexico, with Rimes sharing plenty of posts declaring her love for Cibrian.
"Happy 5 year anniversary to my lover, my friend, my heart, my everything! We have walked through hell and back to be together and wouldn't change a thing. Our bond is like no other. I cherish you!" she captioned a photo from their wedding.
The "Spitfire" singer followed up by posting a picture of herself and Cibrian in the water Sunday, writing, "Happy times @jprensena thnx for the pic #sun #vacation #hubby #allsmiles."
Rimes and Cibrian met on the set of the Lifetime movie Northern Lights and started dating while they were married to Dean Sheremet and Brandi Glanville, respectively. The couple acknowledged the affair before marrying on April 22, 2011.
Cibrian shares two sons, 12-year-old Mason and 9-year-old Jake, with Glanville, who is watching the boys while the pair are away. Glanville, who clashed with Rimes in the past, surprised fans by congratulating the couple Saturday.
"@leannrimes Happy anniversary Happy 2watch my boys 4 mybaby daddy so that y'all can celebrate! Get a tan for me #feeling pasty(mean it)," the 43-year-old reality star tweeted.
"@BrandiGlanville Thank you! Happy that we always pick up where the other leaves off. Xoxo," Rimes responded.
The friendly exchange is a far cry from when Glanville claimed Rimes purposely hurt her feelings by posting photos with her kids over the holidays. The Real Housewives of Beverly Hills star is reportedly dating former Road Rules star Theo Von.