Walla Walla speak English.

Historically, they spoke Sahaptin, which today has less than 100 speakers.

Sahaptin (or Shahaptin) is a language family that includes the Nez Perce, Umatilla, Palouse, Tenino, Cayuse, Klickitats, Wanapums, Walla Walla and Yakama (or Yakima). They were very widespread but historically mainly occupied territory in western Idaho and neighbouring parts of Washington and north-eastern Oregon, including the Snake, Salmon and Clearwater rivers.

The Yakama lived in south-central Washington state; they were the westernmost of all the Sahaptin tribes.

The Yakama people spoke Yakama, which is a northwestern dialect of Sahaptin, a Sahaptian language of the Plateau Penutian family.

Since the late 20th century, some native speakers have argued to use the traditional Yakama name for this language, Ichishkíin Sínwit. The tribal Cultural Resources program wants to replace the word Sahaptin, which means "stranger in the land".

Today, there are less than 90 native speakers of Yakama.