The golf equipment manufacturer wants Timberlake to promote the 2012 RAZR line of equipment, which includes a new driver. He's working on an advertising campaign in Las Vegas for the gear, which will go on sale in the first quarter of next year.
The former N'Sync star became the company's first non-tour player to be appointed as a staff professional in 2008.
"We have worked with Justin for more than three years now and have been thoroughly impressed with the level of quality he brings to everything he is involved with," said Jeff Colton, Callaway's senior vice president of global brand and product.
"Justin is an extremely gifted artist and an avid golfer with a deep passion for Callaway products, and his creative energy will serve us well as we connect with the next generation of golfers,'' Colton said.
The celebrity hosts the Justin Timberlake Shriners Hospitals for Children Open PGA Tour event in Las Vegas and owns a country club near his hometown of Memphis.