Although political ideology has been examined extensively as a predictor of individual differences, it has been absent in the interpersonal relationships literature. Political ideology may have strong effects on friendship patterns because of its polarizing nature. Findings among actual friendship groups (Study 1) indicated a degree of similarity in peers’ political ideology alignments, but also suggested that liberals and conservatives were comfortable with some level of bipartisanship among their friends. In an experimental condition with hypothetical peers (Study 2), individuals’ political ideology predicted their reported friendship potential (perceived similarity and desire for friendship) with gay-affirming and gay-disapproving peers whose ideologies were not explicitly indicated. This effect of political ideology on friendship potential was significant over and above the effect predicted by individuals’ similarity or dissimilarity on sexual minority attitudes with these peers. Findings highlight the overarching relevance of political ideology as a factor that contributes to friendship patterns.