Providing an explanation is a communicative act. It involves an explainee, a person who receives an explanation, and an explainer, a person (or sometimes a machine) who provides an explanation. The majority of research on explanation has focused on how explanations alter explainees’ beliefs. However, one general feature of communicative acts is that they also provide information about the speaker (explainer). Work on argumentation suggests that the speaker’s reliability interacts with the content of the speaker’s message and has a significant impact on argument strength. In five experiments we explore the interplay between explanation, the explainee’s confidence in what is being explained, and the explainer’s reliability. Experiment 1 replicates results from previous literature on the impact of explanations on an explainee’s confidence in what is being explained using real-world explanations. Experiments 2 and 3 show that providing an explanation not only impacts the explainee’s confidence about what is being explained but also influences beliefs about the reliability of the explainer. Additionally, the two experiments demonstrate that the impact of explanation on the explainee’s confidence is mediated by the reliability of the explainer. In Experiment 4, we experimentally manipulated the explainer’s reliability and found that both the explainer’s reliability and whether or not an explanation was provided have a significant effect on the explainee’s confidence in what is being explained. In Experiment 5, we observed an interaction between providing an explanation and the explainer’s reliability. Specifically, we found that providing an explanation has a significantly greater impact on the explainee’s confidence in what is being explained when the explainer’s reliability is low compared to when that reliability is high. Throughout the study we point to the important impact of background knowledge, warranting further studies on this matter.