Thin Air is British singer-songwriter Peter Hammill's 32nd solo album, released on his own Fie!

The main theme of the album is disappearance, as Hammill told British music magazine Mojo in February 2009: "it became apparent fairly quickly that strong thematic links were running through the songs' lyrics: disappearance, change, loss, dislocation in various forms were stitched through all of them.

"[3] Another topic reappearing in several songs is the one of the World Trade Center along with images of planes, though Hammill denied "any direct" reference to 9/11.

[4] According to François Couture of AllMusic, Thin Air: "... may be less experimental than Singularity, but bleaker – and a more cohesive, consistent artistic proposition."

[5] The album's cover was again created by Paul Ridout, using stills from his video work "Minutely Observed Horizon".