Objective The purpose of this study was to characterize the urinary microbiota in women who are planning treatment for urgency urinary incontinence and to describe clinical associations with urinary symptoms, urinary tract infection, and treatment outcomes. Study Design Catheterized urine samples were collected from multisite randomized trial participants who had no clinical evidence of urinary tract infection; 16S ribosomal RNA gene sequencing was used to dichotomize participants as either DNA sequence-positive or sequence-negative. Associations with demographics, urinary symptoms, urinary tract infection risk, and treatment outcomes were determined. In sequence-positive samples, microbiotas were characterized on the basis of their dominant microorganisms. Results More than one-half (51.1%; 93/182) of the participants' urine samples were sequence-positive. Sequence-positive participants were younger (55.8 vs 61.3 years old; P =.0007), had a higher body mass index (33.7 vs 30.1 kg/m2; P =.0009), had a higher mean baseline daily urgency urinary incontinence episodes (5.7 vs 4.2 episodes; P <.0001), responded better to treatment (decrease in urgency urinary incontinence episodes, -4.4 vs -3.3; P =.0013), and were less likely to experience urinary tract infection (9% vs 27%; P =.0011). In sequence-positive samples, 8 major bacterial clusters were identified; 7 clusters were dominated not only by a single genus, most commonly Lactobacillus (45%) or Gardnerella (17%), but also by other taxa (25%). The remaining cluster had no dominant genus (13%). Conclusion DNA sequencing confirmed urinary bacterial DNA in many women with urgency urinary incontinence who had no signs of infection. Sequence status was associated with baseline urgency urinary incontinence episodes, treatment response, and posttreatment urinary tract infection risk.