The purple martin is a large North American swallow that suffered a severe population crash in the 20th century due to nesting competition from invasive species. We screened an enriched DNA library for microsatellites from purple martins (Progne subis subis). Ten loci consistently amplified and were polymorphic with an allele range of 2-19 and observed heterozygosity ranged from 0.31 to 0.93. Two loci are sex-linked, and two additional loci failed to meet Hardy-Weinberg expectations likely due to the presence of null alleles. These polymorphic microsatellite loci can be used for studies of genetic diversity, population structure, and relatedness, all of which have been suggested to determine the impact of substantial regional declines in population density.