Ciara went all out for Russell Wilson's 34th birthday ... hittin' a super sexy dance for her hubby -- AND penning him a sweet love letter, too!!!
Wearing a skintight, leather mini-dress, the "Level Up" singer took to TikTok to show love for her NFL player boo ... dancing around to a birthday song while blowing him a kiss.
She later hit Instagram to tell the Denver Broncos quarterback just how much she loved him on his big day Tuesday.
"Intelligent, Beautiful, Loving, Caring, Thoughtful, Consistent, Special, Anointed, Rare, A Legend, a Winner, Everything that is YOU!