Currently, no validated instrument exists for assessing the subjective experience of orgasm in the gay population. The Orgasm Rating Scale (ORS), previously validated in the heterosexual population, comprises four dimensions: Affective, Sensory, Intimacy, and Rewards. This study validated it for sexual relationships in the gay population by obtaining its factorial invariance by sexual orientation and sex, its internal consistency reliability, and evidence of validity in its relationship with other variables. We assessed 1600 cisgender Spanish adults–heterosexuals, gays, and lesbians–divided into 4, sex-based groups of 400 each, according to the Kinsey scale scores. Participants reported recent experiences of orgasm in the context of sexual relationships and responded to the ORS and other scales assessing attitude toward sexual fantasies and sexual functioning. The ORS structure showed a strict multigroup-level invariance by sexual orientation and sex, confirming its four-dimensional structure. The subjective orgasm intensity was associated with a positive attitude toward sexual fantasies and sexual functioning. Scores obtained on the Affective, Intimacy, and Rewards dimensions confirmed the ability to discriminate between gay people with and without orgasmic difficulties. The ORS’s Spanish version presents good psychometric properties as a validated scale to evaluate the subjective experience of orgasm in the gay population.