I used the framework of the personality-relationship transaction to examine the co-development of personality and relationship quality during college in three different relationship contexts: an aggregate of friends, romantic partner dyads, and friend dyads. I treat the personality-relationship transaction as a dyadic process, rather than an ego-centric one, by including friends’ and romantic partners’ reports of personality and relationship quality. I created a multivariate latent growth curve model version of the Actor Partner Interdependence Model to test how personality and relationship quality co-developed. Initial correlations between personality and relationship quality reflect what is seen in previous work; self-reported extraversion, agreeableness, conscientiousness, and openness are positively correlated with friendship quality, and openness is negatively correlated with romantic relationship quality. There were very few associations between initial personality and relationship quality and changes in either domain. A notable exception was that changes in openness to experience were influenced by relationship quality in all three relationship contexts. Changes in personality and relationship quality were uncorrelated in all three relationship contexts. Overall, the results suggest that personality and relationships develop independently of each other, after taking their initial associations into account