Extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) represent a major threat to public health. Little is known on their potential for sexual transmission. We recruited individuals at a sexually transmitted infection and human immunodeficiency virus (HIV) outpatient clinic in Paris, France, in whom we evaluated the prevalence of ESBL-E intestinal carriage and, among those testing positive, the proportion with clearance 6 months thereafter. We compared carriage prevalence between groups using logistic regression adjusted for age, geographic origin, travel outside Europe, and antibiotic use in the past 6 months. A total of 2157 individuals participated, of whom 226 (10.5%) were ESBL-E carriers. The proportions of ESBL-E carriers varied across sexual groups and were as follows: HIV-negative men who have sex with men (MSM) and who were on preexposure prophylaxis (PrEP), 16.3% (41 of 251); HIV-negative MSM not on PrEP, 9.7% (47 of 487); HIV-positive MSM, 12.2% (61 of 500); HIV-negative men who have sex exclusively with women, 10.0% (44 of 439); and HIV-negative women who have sex with men, 6.9% (n = 33 of 480). After adjustment, ESBL-E prevalence was significantly higher in HIV-negative MSM on PrEP (P < .001) and HIV-positive MSM (P = .01) than in women who have sex with men. A higher number of sexual partners in the past 6 months was associated with ESBL-E carriage after adjustment (P = .004). Escherichia coli sequence type 14 and blaSHV-12-producing ESBL-E were observed only in MSM. Of 102 individuals with ESBL-E returning for testing, 26 (25%) had carriage at 6 months. ESBL-E carriage is more frequent in MSM undergoing PrEP or living with HIV and with increasing number of sexual partners. More research is warranted to understand the consequences of ESBL-E carriage in these populations and how transmission can be reduced.