Within the field of research examining stress reactivity, there have been recent strides to modify the Trier Social Stress Test (TSST) to be administered remotely, with user-friendly and accessible means of collecting physiological measures of an acute stress response. Research regarding stress reactivity often examines stress buffering, the phenomena wherein the experience of an acute stressor is dulled or recovery is assisted by environmental factors. Within the home environment, a household pet may be considered a source of stress buffering. This study examined whether interactions with a household pet before and after a novel, internet-delivered adaptation of the TSST (iTSST) may result in a blunted acute stress response, collected through photoplethysmography via Smartphone, and self-reported stress and anxiety (390 recruited, n = 291). As well, this study examined if pet attachment, species of pet, and pre-existing mental health and environmental factors influence the extent to which stress buffering may occur (n = 66). Results indicated that individuals who interacted with a pet cat, but not a pet dog, demonstrated a blunted response to the iTSST. As well, occurrences of behaviours that were observed during an owner’s interaction with their pet dog or cat were similar before and after the iTSST, suggesting that these behaviours may be an expression of trait-like characteristics. Finally, owner gender and timepoint during the experiment best accounted for variance in data between participants. Results support the idea that pets may be beneficial in attenuating acute stress responses.