Friendship quantity and quality are related to adolescent loneliness, but the exact link between these constructs is not well understood. The present study aimed to examine whether adolescents' perception of friendship quantity and quality, and the perceptions of their peers, were related to loneliness. We examined the relation between loneliness and the number of unilateral and reciprocal friendships and compared the views of best friendship quality. Overall, 1,172 Dutch adolescents (49.1% male, M age = 12.81, SD = .43) nominated their friends and rated their friendship quality. Friendship quantity was measured using sociometrics to distinguish reciprocated and unilateral (i.e., one-sided) friendships. The analyses indicated that loneliness was related to fewer reciprocal and unilateral-received friendships (i.e., the adolescent received a friendship nomination but did not reciprocate that nomination) and a lower quality of best friendship. Actor-partner interdependence analyses revealed that adolescents' loneliness was related to a less positive evaluation of their friendship, as reported by adolescents themselves (i.e., a significant actor effect) but not by their friends (i.e., nonsignificant partner effect). These findings (a) indicate that loneliness is negatively related to the number of friends adolescents have, as perceived by themselves and their peers and (b) suggest that, once a friendship is established, lonely adolescents may interpret the friendship quality less positively compared to their friends. Implications of these findings for our current understanding of adolescent loneliness are discussed, and suggestions for future research are outlined.