The Kratos XQ-58 Valkyrie is an experimental stealth unmanned combat aerial vehicle (UCAV) designed and built by Kratos Defense & Security Solutions for the United States Air Force's Low Cost Attritable Strike Demonstrator (LCASD) program, under the USAF Research Laboratory's Low Cost Attritable Aircraft Technology (LCAAT) project portfolio.

[1] The XQ-58 Valkyrie fell within the USAF Research Laboratory's Low Cost Attritable Aircraft Technology (LCAAT) portfolio, whose objectives included designing and building unmanned combat aerial vehicles (UCAVs) faster, by developing better design tools and maturing and using commercial manufacturing processes to reduce production time and cost.

[2][3] The LCAAT was eventually turned into the Off-Board Sensing Station (OBSS) program, which Kratos was awarded a contract for in 2021 but lost out to General Atomics in 2023, which developed the XQ-67A.

[1] On 23 July 2020, the Air Force gave contracts to Kratos, Boeing, Northrop Grumman, and General Atomics to compete for the Skyborg program, an effort to field an unmanned wingman for manned fighters, at a price that makes it somewhat expendable.

[16][17] In March 2021, the XQ-58A completed its sixth test flight, opening the doors of its internal weapons bay for the first time and releasing a 27 lb (12 kg) Area-I Altius-600 small unmanned aircraft system (UAS).