Children's (5‐, 7‐ to 8‐, and 10‐ to 11‐year‐olds), and adolescents’ (13‐ to 14‐year‐olds) judgments and reasoning about same‐sex romantic relationships were examined (N = 128). Participants’ beliefs about the acceptability and legal regulation of these relationships were assessed, along with their judgments and beliefs about excluding someone because of his or her sexual orientation and the origins of same‐sex attraction. Older participants evaluated same‐sex romantic relationships more positively and used more references to personal choice and justice/discrimination reasoning to support their judgments. Younger participants were less critical of a law prohibiting same‐sex relationships and were more likely to believe it was not acceptable to violate this law. Beliefs about origins of same‐sex attraction showed age‐specific patterns in their associations with evaluations.