WASH (97.1 MHz) is a commercial FM radio station owned and operated by iHeartMedia and located in Washington, D.C. Known on-air as "WASH-FM", the station airs an adult contemporary radio format. Studios and offices are on Rockville Pike (Maryland Route 355) in Rockville, Maryland. The station has an effective radiated power (ERP) of 17,500 watts, broadcasting from a tower at 242 metres (794 ft) in height above average terrain (HAAT). The transmitter site is on Chesapeake Street NW off Wisconsin Avenue in the Tenleytown neighborhood of Washington, D.C. With a good radio, WASH coverage extends from Baltimore to Fredericksburg, Virginia.

WASH broadcasts using HD Radio technology. Its HD2 digital subchannel carries the Air1 contemporary Christian music channel from the Educational Media Foundation, and its HD3 subchannel formerly carried iHeartRadio's "The Breeze" Soft AC format. WASH streams its programming on the iHeartRadio platform.

Weekdays begin with the Toby & Chilli morning show, followed by Jenni Chase in middays and Sabrina Conte in afternoons. In the evening, WASH carries the syndicated Delilah show, featuring music requests and call-ins. Weekends include the syndicated Ellen K Show and Back Trax USA with Kid Kelly. For much of November and December, the station switches to Christmas music (as well as on July 25 for "Christmas in July") and calls itself "Washington's Home For The Holidays" during the holiday season.

WASH evolved from an experimental FM station, W3XL, which was first licensed in September 1945. The station was operated by the Commercial Radio Equipment Company, which had been founded by Everett L. Dillard in Kansas City, Kansas in 1933, and later moved to Washington.

In May 1940, the Federal Communications Commission (FCC) had announced the establishment, effective January 1, 1941, of an FM band operating on 40 channels spanning 42–50 MHz. In 1945 the FCC began the process of reassigning the original FM band frequencies to other services, and ordered existing stations to move to a new band from 88 to 106 MHz, which was later expanded to 88–108 MHz. W3XL, transmitting on 98.9 MHz, was one of the first stations to broadcast on a "high band" frequency. By November 1946 the station was operating on a regular schedule of 3 to 11 p.m.

As of 1945 there were no commercial FM stations in the Washington area, with the only local FM broadcasters consisting of two experimental authorizations: W3XL, plus the WINX Broadcasting Company's W3XO, which had begun operations in 1939. In October 1945, Everett Dillard filed an application to convert W3XL into a commercial station. A construction permit was granted the following September, and initially assigned the call letters WSDC, which were changed to WASH two months later, prior to the station beginning operations. WASH debuted as Washington's second commercial FM station at 6:30 p.m. on December 17, 1946. (W3XO had already been converted into Washington's first commercial station, originally as WINX-FM, and started regular broadcasts in September 1946.) In the early era of FM broadcasting, most stations were co-owned with an AM station and often simulcast its programming, when few listeners had FM receivers. WASH was a rare stand-alone FM outlet. Everett Dillard served as the president and general manager, and studios were located at 1319 F Street NW.

WASH's assignment was for operation on 101.3 MHz. However, it received a special temporary authority to broadcast on 98.9 MHz with reduced power, employing W3XL's transmitter in Northwest Washington. WASH was reassigned to its current frequency, 97.1 MHz, in mid-1947 without ever broadcasting on 101.3. From September 16, 1947, through May 3, 1950, the station relayed BBC Overseas Service programming and thrice-daily time signals from WWV via shortwave while it constructed a studio.

From September 18, 1958, through March 31, 1959, it was granted unusual permission to operate as a non-commercial station, identified by the experimental call sign KG2XIG instead of its normal call sign.