The Wedell-Williams XP-34 was a fighter aircraft design submitted to the United States Army Air Corps (USAAC) before World War II by Marguerite Clark Williams, widow of millionaire Harry P. Williams, former owner and co-founder of the Wedell-Williams Air Service Corporation.

[2] The forward fuselage was intended to be metal, the after part and control surfaces covered in fabric.

[2] On 1 October 1935, the USAAC ordered a full set of drawings and issued the XP-34 designation.

It soon became apparent, however, with its original 700 hp (522 kW) Pratt & Whitney R-1535 Twin Wasp Junior engine, the anticipated performance of the XP-34 would be insufficient compared to designs already in production.

Although the promise of high speed was still there, other considerations such as the complete redesign of the airframe to accommodate a heavier and more powerful engine were considered impractical with the new design subsequently rejected by the Air Corps before any aircraft were built.