This article presents two studies that tested the predictive validity of intergroup contact theory and secondary transfer effects related to pre-service teacher attitudes toward sexual minority youth in classrooms. Multiple regression of feeling thermometer scores in Study 1 (N = 989) suggested that more favorable attitudes are present among younger, female, bisexual or homosexual, less religious, politically left-wing pre-service teachers with lesbian, gay, and bisexual contacts. Associations with family membership and hometown size were nonsignificant. Analyses of variance in Study 2 (N = 406) showed statistically significant secondary transfer effects. For instance, teacher candidates with no lesbian women contacts showed less sexual prejudice toward lesbian students if they were in social contact with gay men and bisexual people. Implications for teacher education, teacher professionalism, and the need to create safe spaces in school for LGBTQIA+ students are discussed.