Adna is an unincorporated community located in Lewis County, Washington. The community was originally known as Pomona.
Adna's current name was established in 1892 when the United Railroads of Washington branch of the Northern Pacific Railroad Company laid down railroad tracks through the area. Along with the arrival of the railroad came the building of a new post office which had yet to be named. URW engineer W. C. Marion chose the name "Edna" in honor of local resident Edna Browning, but the name was rejected by the US postal Service as there was, at the time, already a post office named Edna in Washington. The Postal Service changed the name from "Edna" to "Adna".