The 40-year-old record producer has worked on tracks for Missy Elliott, Justin Timberlake, Kelly Rowland and a host of other stars, reported Contactmusic.
Jay posted a picture of them together on his Life + Times blog, with a caption reading, "We would like to welcome Timbaland to the Roc Nation family."
Timbaland, whose real name is Timothy Mosley, also tweeted about the move.
"Just want to thank everybody who is congratulating me on my new business venture. I appreciate it. Big moves, new beginnings at Roc Nation," he posted.
Timbaland has also previously produced tracks for Jay - who founded Roc Nation in 2008, including hits 'Big Pimpin' and 'Dirt Off Your Shoulder'.
His most recent collaboration saw him team up with Justin Timberlake on his new single, 'Suit & Tie' and he is also expected to release a new solo album this year.