Ithamara Koorax (born April 28, 1965) is a Brazilian jazz and pop singer. For several years, she was voted one of the best jazz singers of the world by DownBeat Readers Polls. In 2008 and 2009, Koorax placed third on the "Female Vocalist" category on the 73rd DownBeat Readers Polls, with Diana Krall on the first place and Cassandra Wilson on second, (DownBeat's December 2008 issue, page 44), as well as on the 74th Annual Readers Poll (December 2009 issue, page 42).

Back in 2002, Koorax had already placed fourth in the 67th Annual DownBeat Readers Poll (December 2002 issue, page 56).

Koorax once again appeared many times as one of the top singers from the 65th DownBeat Readers Poll (December 2000, page 54), to the 77th Annual Readers Poll (category Female Vocalist, page 60) , receiving similar acclaim in magazines from the UK (Jazz Journal), France (Jazz Hot), Japan (Swing Journal), Korea (Jazz People) and Switzerland (Jazz 'n' More), among others. In the January 2012 issue of DownBeat magazine (page 48, list of "Best CDs of 2011", her album "O Grande Amor", recorded in Europe with the Peter Scharli Trio, was voted one of the best releases of 2011, receiving a four and one half raving review. In the January 2008 issue of DownBeat (page 54, list "Best CDs of 2007"), her "Brazilian Butterfly" album was voted one of best releases of 2007, receiving a 4-star review.