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 former "LeAnn & Eddie" reality show stars 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.
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"@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.
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