Thompson Sound (Māori: Te Awa-o-Tū; officially Te Awa-o-Tū / Thompson Sound) is a fiord of the South Island of New Zealand.

The fiord is connected at its farthest extent with Pendulo Reach,[1] part of Doubtful Sound / Patea, and between them Thompson and Doubtful Sounds form the non-Tasman Sea coast of Secretary Island.

[1] Thompson Sound was given its European name by John Grono, a sealer who worked the Fiordland coast in the early 19th century, after his boat's owner, Andrew Thompson.

Later surveyor Captain John Stokes incorrectly thought that the sound had been named after Colonial Secretary Edward Deas Thomson, and named an indentation in the sound's Secretary Island coast as Deas Cove.

[2] In October 2019, the name of the fiord was officially altered to Te Awa-o-Tū / Thompson Sound.