Intimate partner violence (IPV) is alarmingly prevalent among sexual and gender minority youth assigned female at birth (SGM-AFAB), making it important to identify risk factors that can be targeted in prevention efforts for this population. Although several relationship-level risk factors for IPV have been identified in different-sex couples, research on SGM-AFAB is sparse and predominantly cross-sectional. The present study used seven waves of data from a longitudinal cohort study of SGM-AFAB youth (n = 463) to explore relationship factors (relationship quality, destructive conflict, and self- and partner-jealousy) as risk factors for perpetration and victimization of three types of IPV (physical, psychological, and coercive control). At each wave, participants reported on relationship factors and IPV for up to three romantic partners in the past 6 months. Multilevel models tested for associations between the relationship factors and IPV at three levels: between-persons, within-persons across time (wave), and within-persons across relationships. Relationship quality was associated with IPV mostly at the between-persons and within-persons (wave) levels. Couple conflict was associated with all IPV outcomes at all levels. Partner jealousy was more consistently associated with IPV victimization; participant jealousy was more consistently linked with IPV perpetration. These novel findings suggest that, within SGM individuals, IPV may be influenced by relationship quality, destructive conflict, and jealousy as they fluctuate within individuals from relationship to relationship and within individuals over time. As such, these relationship factors represent promising potential targets for interventions to reduce IPV among SGM-AFAB youth.