Tichina Arnold Files for Divorce 5.5 Years After Separating

Tichina Arnold says she split from her husband at the beginning of 2016 following his sex tape scandal with another woman ... but she's just now pulling the trigger on officially ending her marriage.

According to new legal docs, obtained by TMZ ... "The Neighborhood" and "Martin" star filed for divorce from Rico Hines this week, citing the usual irreconcilable differences.

What's unusual, however, is the timing of this divorce -- Tichina lists the separation date as January 12, 2016 ... about 3-and-a-half years after they wed in 2012.

If you don't recall ... the actress announced she was divorcing Rico back then, and memorably claimed it was due to discovering he made a sex tape with another woman.

Hines is a longtime basketball coach, currently on the staff of the Sacramento Kings.