Introduction: Despite the high cannabis use rates among sexual minority (SM) individuals, less research has examined factors related to cannabis use among SM (vs. heterosexual) individuals, especially in places with legal medical cannabis retail markets and high structural stigma, like Oklahoma. Methods: Data were from a survey of Oklahoma adults, including 3020 females (18.6% SM) and 2279 males (10.1% SM). Bivariate analyses examined associations of sexual identity with cannabis-related factors (i.e., perceived harm, positive attitudes, marketing exposure, depressive symptoms, anxiety symptoms) and cannabis use and use severity (i.e., past 30-day use, daily/near-daily use, cannabis use disorder [CUD] symptoms). Logistic regression examined associations of sexual identity and cannabis-related factors with cannabis use and use severity among females and males, separately. Results: SM (vs. heterosexual) females reported greater odds of past 30-day cannabis use and daily/near-daily use, lower harm perceptions, greater marketing exposure, and higher rates of depressive/anxiety symptoms. Lower harm perceptions and greater marketing exposure were associated with greater odds of past 30-day use, whereas marketing exposure was associated with greater odds of daily/near-daily use. SM (vs. heterosexual) males reported greater odds of daily/near-daily use and higher rates of depressive/anxiety symptoms. Conclusions: SM (vs. heterosexual) females reported higher rates of cannabis use, whereas SM (vs. heterosexual) females and males reported higher rates of daily/near-daily cannabis use. Potential targets for cannabis-related health campaigns aimed at reducing use differences include correcting misinterpretations of harm that may emanate from cannabis marketing efforts among females and addressing depressive symptoms among males.