This trend study analyzes nine years (from 2011-2019) of cross-sectional survey responses to Klein’s Sexual Orientation Grid (1978) to explore changes in sexual orientation among emerging adult college students. Categorical regression models based on ordinal responses revealed that participants were moving away from exclusively heterosexuality on attraction, behavior, and identity subscales at a rate of approximately 6% per year. This trend augments for women after 2014, coinciding with increased advocacy efforts related to U.S. marriage equality, but attenuates for men. Participants' race also related to variations in sexual orientation: Black participants were less likely than White participants to identify as exclusively heterosexual, whereas the pattern reversed for Asian participants relative to White participants. These findings suggest that changes in sexual orientation are occurring among emerging adults in the U.S., potentially in response to changing social and political contexts, but these changes are more pronounced in women and Black emerging adults.