Sexually transmitted infections (STIs) are widespread worldwide and negatively affect sexual and reproductive health. Gaps in evidence and in available tools have long hindered STI programmes and policies, particularly in resource-limited settings. In 2022, WHO initiated a research prioritisation process to identify the most important STI research areas to address the global public health need. Using an adapted Child Health and Nutrition Research Initiative methodology including two global stakeholder surveys, the process identified 40 priority STI research needs. The top priorities centred on developing and implementing affordable, feasible, rapid point-of-care STI diagnostic tests and new treatments, especially for gonorrhoea, chlamydia, and syphilis; designing new multipurpose prevention technologies and vaccines for STIs; and collecting improved STI epidemiologic data on both infection and disease outcomes. The priorities also included innovative programmatic approaches, such as new STI communication and partner management strategies. An additional six research areas related to mpox (formerly known as monkeypox) reflect the need for STI-related research during disease outbreaks where sexual transmission can have a key role. These STI research priorities provide a call to action for focus, investment, and innovation to address existing roadblocks in STI prevention, control, and management to advance sexual and reproductive health and wellbeing for all.