The Great Unknown is the third solo studio album by the Matchbox Twenty lead singer Rob Thomas, released on August 21, 2015, through Atlantic Records.

"[3] The Boston Globe's Sarah Rodman wrote that on The Great Unknown, the singer continues his career of composing, "catchy melodies, lyrics straightforward in their universality, and crisp production".

In a more mixed review, Chuck Arnold of Rolling Stone wrote, "Rob Thomas remains a known quantity on his third solo album.

While that means there aren't many surprises, the good news is he's still the same consummate pop-rock craftsman who has been making it all sound so smooth for years.

The arrangements, likewise, have a slick adaptability that makes these songs serviceable cover material for any pop star of the hour.