The former African player of the year, 34, has been training with Chelsea's reserve team for the last six months and will wear the No.5 shirt for his new team after penning a one year deal with the option of an extension.
He told the club's official website:
"I hope I am the prelude to other world players moving to Indonesia. "Hopefully this is a good beginning for Indonesian football and also for Persib. Thank you for bringing me here. I'm excited and want to give my best."
Essien made over 250 appearances during his playing days with Chelsea and is highly respected at the club. Congrats to him!