The effect of risk factors on ovarian cancer differs by histotype, and the prevalence of such risk factors varies by race/ethnicity. It is not clear how ovarian cancer incidence has changed over time by histotype and race/ethnicity. We used the Surveillance, Epidemiology, and End Results Program (SEER-12) 1992-2019 data to examine the trend of ovarian cancer incidence for three histotypes (high-grade serous N = 19,691, endometrioid N = 3,212, and clear cell N = 3,275) and four racial/ethnic groups (Asian/Pacific Islander, Hispanic, non-Hispanic Black, and non-Hispanic White). Joinpoint and age-period-cohort analyses were conducted to analyze ovarian cancer incidence trends. High-grade serous cancer was the most common histotype, but its incidence has significantly decreased over time for all racial/ethnic groups; the decrease was largest for non-Hispanic White women (average annual percent change AAPC during 2010-2019 = -6.1; 95% confidence interval (CI), -8.0 to -4.2). Conversely, clear cell cancer was most common in the Asian/Pacific Islanders, and its incidence has increased over time, particularly among Hispanic and Asian/Pacific Islander women (AAPC during 2010-2019 = 2.8; 95% CI, 0.8 to 4.7, and AAPC = 1.5; 95% CI, 0.7 to 2.2, respectively). Endometrioid cancer incidence has decreased in non-Hispanic White but increased in Hispanic women (AAPC during 2010-2019 = -1.3; 95% CI, -1.9 to -0.8, and AAPC = 3.6; 95% CI, 1.0 to 6.3, respectively). The differential incidence trends by histotype and race/ethnicity underscore the need to monitor incidence and risk factor trends across different groups and develop targeted preventive interventions to reduce the burden of ovarian cancer and disparity by race/ethnicity. During 1992-2019, high-grade serous ovarian cancer incidence has decreased while clear cell cancer incidence has increased regardless of race/ethnicity. Endometrioid cancer incidence has decreased in non-Hispanic White but increased in Hispanic women. Differential ovarian cancer incidence trends highlight the need for targeted preventive interventions by histotype and race/ethnicity.