Background: Surgical site infection (SSI) after total knee arthroplasty (TKA) is associated with increased morbidity and healthcare expenditures. During the coronavirus disease-2019 (COVID-19) pandemic, our institution intensified hygiene standards, including greater glove, personal protective equipment (PPE), and mask use. We assessed the effect of these changes on SSI rates in primary total knee arthroplasty (pTKA) and revision total knee arthroplasty (rTKA). Patients and Methods: A retrospective review was performed identifying TKA from January 2019 to June 2021 at a single institution. Baseline characteristics and outcomes were compared before (January 2019 to February 2020) and during (May 2020 to June 2021) the COVID-19 pandemic when no restriction on operative services was in place and were further analyzed during the first (May 2020 to November 2020) and second (December 2020 to June 2021) periods after full operative services were restored. Results: A total of 3,398 pTKA (pre-pandemic: 1,943 [57.2%]; pandemic: 1,455 [42.8%]) and 454 rTKA (pre-pandemic: 229 [50.4%]; pandemic: 225 [49.6%]) were included. For primary cases, superficial and deep SSI rates were similar before and during COVID-19; however, for revision TKA, the incidence of all (-0.32%, p = 0.035) and superficial (-0.32%, p = 0.035) SSIs decreased during COVID-19. Primary TKA had longer operative times (p < 0.001) and shorter length of stay (LOS; p < 0.001) during COVID-19. Both pTKA (p < 0.001) and rTKA (p = 0.003) were discharged to skilled nursing facilities less frequently during COVID-19 as well. Conclusions: After our hospital implemented COVID-19-motivated hygienic protocols, superficial SSI rates decreased in rTKA but not in pTKA. During COVID-19, patients were less likely to be discharged to skilled nursing facilities, and pTKA operative times increased. Although these changes occurred during intensified hygiene protocols, further research is needed to determine how these factors contributed to the observed changes.