Nostalgia, a sentimental longing for the past, increases well-being, especially in response to psychological imbalance (e.g., negative affect, loneliness). Recent work has examined how nostalgia for times shared with a romantic partner (i.e., relationship nostalgia) also has positive effects. The two present studies, both conducted with Amazon Mechanical Turk samples, explored whether relationship nostalgia buffers the negative effect of partner conflict on relationship commitment. In Study 1 (N = 137), results of a moderated regression analysis showed that the negative link between conflict and commitment was offset by participants' higher relationship nostalgia proneness. Study 2 (N = 769) built on these correlational findings with an experimental design. Specifically, for participants randomly assigned to a relationship nostalgia writing condition, the negative link between conflict and commitment was weaker than it was for participants who wrote about a positive or ordinary past event. These studies demonstrate the potential for relationship nostalgia to maintain commitment in response to the threat of partner conflict.