The competing demands of the military can adversely affect the relationships of military couples. However, there is little U.K. research, and most research focuses only on the role of personnel mental health on relationship outcomes. Data from 219 female partner/male military personnel couples collected during a study of military-connected children (2010–2012) were used to determine relationship distress among U.K. serving military couples (Dyadic Adjustment Scale–7 < 21). Dyadic analyses were used to examine associations between individual couple member Dyadic Adjustment Scale–7 scores and sociodemographic, military, and health factors. 29.2% of personnel and 26.9% of partners met criteria for relationship distress; 41.5% of couples contained at least one member who met criteria. Relationship satisfaction was associated with relationship satisfaction in the other couple member (β = 0.460), partner posttraumatic stress disorder scores (β = −0.276), and lower personnel rank (β = −0.344). Partners of personnel of lower rank and personnel with increased posttraumatic stress disorder symptoms may be more at risk of lower relationship satisfaction. Findings highlight the importance of examining the mental health of both serving and nonserving couple members when examining military family outcomes given the impact of partner health on personnel relationship satisfaction. Additional information should be provided to military partners and couples on the realities of Service life prior to joining, with greater advertisement of military initiatives to raise awareness of available services for personnel and their partners.