Individuals sometimes alter their self-views to be more similar to others—traditionally romantic partners—because they are motivated to do so. A common motivating force is the desire to affiliate with a partner. The current research examined whether a different motivation—romantic jealousy—might promote individuals to alter their self-views to be more similar to a romantic rival, rather than a partner. Romantic jealousy occurs when individuals perceive a rival as a threat to their relationship and motivates individuals to defend their relationship. We proposed that one novel way that individuals might defend their relationship is by seeing themselves as more similar to a perceived romantic rival. We predicted individuals would alter their self-views to be more similar to a rival that they believed their partner found attractive. Importantly, we predicted that state romantic jealousy would motivate these self-alterations. Three studies confirmed these hypotheses.