BACKGROUND: To describe changes in reported sexually transmitted diseases (STDs) during the U.S. coronavirus disease 2019 pandemic, we compared the weekly number of reported nationally notifiable STDs in 2020 to 2019. METHODS: We reviewed cases of chlamydia, gonorrhea, and primary & secondary (P&S) syphilis reported to the U.S. National Notifiable Disease Surveillance System in 2020. For each STD, we compare the number of 2020 cases reported for a given Morbidity and Mortality Weekly Report (MMWR) week to the number of 2019 cases reported in the same week, expressing 2020 cases as a percentage of 2019 cases. We also calculated the percent difference between 2020 and 2019 cumulative case totals as of MMWR week 50 (week of December 9). RESULTS: During MMWR weeks 1-11 (week of December 29, 2019-March 11, 2020), the weekly number of cases of STDs reported in 2020 as a percentage of the cases in the same week in 2019 were similar. However, 2020 numbers were much lower than 2019 numbers in week 15 (week of April 8; chlamydia, 49.8%; gonorrhea, 71.2%; and P&S syphilis, 63.7%). As of week 50, the 2020 cumulative totals compared to 2019 were 14.0% lower for chlamydia, 7.1% higher for gonorrhea, and 0.9% lower for P&S syphilis. CONCLUSION: During March-April 2020, national case reporting for STDs dramatically decreased compared to 2019. However, resurgence in reported gonorrhea and syphilis cases later in the year suggest STD reporting may have increased during 2020, underscoring the importance of continued STD prevention and care activities.