Between November 2014 and March 2015, five patients presented to a sexual health clinic in England and were diagnosed with gonococcal infection that was highly resistant to azithromycin. Contact tracing identified three additional cases. High-level azithromycin resistance is a rare phenotype previously observed only sporadically in the UK and elsewhere. Whole genome sequencing was performed on seven of the isolates, and it demonstrated that they were identical. The isolates remained susceptible to ceftriaxone, ciprofloxacin, and spectinomycin, and all patients were treated successfully.