In later life, the loss of a spouse due to divorce or widowhood is common and can lead to elevated depressive symptoms and loneliness. Research suggests that companion animal (CA) may be beneficial for psychological health, but limited research has explored whether CA can buffer negative consequences of social losses. This study uses data drawn from the Health and Retirement Study (HRS) to examine changes in depressive symptoms and loneliness in relation to a social loss among those with/without a CA. We used inverse-probability weighted regression to adjust for selection factors and isolate effects of CA ownership on changes in psychological health. Regardless of CA ownership, spousal loss was associated with psychological health consequences. Facing a social loss without a CA was related to statistically greater increases in depressive symptoms relative to those with a pet (2.580 vs. 1.207 symptoms, respectively). Similarly, experiencing a loss was associated with significantly greater increases in loneliness, with statistically greater increases in loneliness among those without a CA (p < .01). However, those with a CA did not experience greater increases in loneliness than those who did not experience a loss. In later life, CA ownership may buffer against the detrimental consequences of major social losses on psychological health. Future research on the therapeutic effects of CA ownership, as well as pet therapy, during other major life stage transitions is needed to help isolate potential mechanisms driving the benefits of human-animal interactions.