Background Social science theories suggest that the legalization of same-sex marriage may lead to improved economic opportunities among sexual minorities. However, empirical evidence pertaining to this issue is scarce. We examined the association between state-level same-sex marriage legalization between 2004 and 2014 and employment outcomes among sexual minority men and women aged 18 years or older (N = 274) in 2015 using the U.S. Medical Expenditures Panel Survey. Results Legalization of same-sex marriage in the U.S. was associated with increased odds of employment among sexual minorities in regression models adjusting for individual-level sociodemographic factors, household–level characteristics, county-level economic and demographic factors, and state-level public attitudes towards sexual minorities. In addition, there was some evidence that the legalization of same-sex marriage may be associated with greater earnings and income among sexual minorities. There were no significant positive associations between same-sex legalization and any of the outcomes when the same analyses were repeated among heterosexual individuals (N = 10,330). Conclusions Our findings provide partial evidence that the legalization of same-sex marriage may have improved socioeconomic outcomes among U.S. sexual minorities.