Urban centers are not where one expects to find new species. Yet, we report here a newly recognized ant, Strumigenys ananeotes sp. nov., in an urban yard in Salt Lake City, Salt Lake County, Utah, USA. The genus Strumigenys is a major radiation of litter ants that are found primarily in the wet tropics and subtropics. They are extremely rare in western North America, known only from sites hundreds of kilometers south and west of Salt Lake City. The new species is related to species from southern Arizona and is presumed native. We propose that it is normally restricted to moist, subterranean microhabitats in an otherwise arid region, but that anthropogenic activity has created an urban forest with summer conditions similar to eastern deciduous forest. Strumigenys ananeotes may now have a greatly expanded habitat and visibility, a case of a native species benefiting from human development rather than being displaced.