Winston, who also serves as president of the NFL Players Association, was released by the club in September.
"Happy to be back in Cincy! WhoDey," Winston tweeted Wednesday morning.
The soon-to-be 34-year-old Winston joins a Bengals club that placed fellow tackle Jake Fisher on the non-football illness list on Wednesday. Fisher exited Sunday's 23-7 loss to the Jacksonville Jaguars with an illness that landed him in the hospital.
Winston started six games for Cincinnati over the last three seasons. He has also played with the Houston Texans, Kansas City Chiefs and Arizona Cardinals during his 12-year NFL career.
Winston was re-elected in 2016 to a two-year term as the NFLPA's president.