Humans are adept at extrapolating emotional information from the facial expressions of other humans but may have difficulties identifying emotions in dogs, compromising both dog and human welfare. Experience with dogs such as through pet ownership, as well as anthropomorphic tendencies such as beliefs in animal minds, may influence interspecies emotional communication, yet little research has investigated these variables. This explorative study examined 122 adult humans’ ability to identify human and dog emotional facial expressions (happiness, fearfulness, anger/aggression) through an online experimental emotion recognition task. Experience with dogs (through current dog ownership and duration of current dog ownership), emotion attribution (through beliefs about animal mind), and demographics were also measured. Results showed that fear and happiness were more easily identified in human faces, whereas aggression was more easily identified in dog faces. Duration of current dog ownership, age, and gender identity did not relate to accuracy scores, but current dog owners were significantly better at identifying happiness in dog faces than non-dog owners. Dog ownership and duration of ownership related to increased beliefs about, and confidence in, the emotional ability of dogs, and a stronger belief in animal sentience was positively correlated with accuracy scores for identifying happiness in dogs. Overall, these explorative findings show that adult humans, particularly current dog owners and those who believe in the emotionality of dogs, can accurately identify some basic emotions in dogs, but may be more skilled at identifying positive than negative emotions. The findings have implications for the prevention of negative human-animal interactions through prevention and intervention strategies that target animal emotionality.