Abstract Effective communication relies on consumers remembering, sharing, and applying relevant information. Source memory, the ability to link a claim to its original source, is an essential aspect of accurate recall, attitude formation, and decision making. We propose that claim objectivity, whether a claim is a fact or an opinion, affects memory for the claim’s source. This proposal follows a two-step process: (i) opinions provide more information about sources than facts do; (ii) claims that provide more information about sources during information encoding are more likely to be accurately attributed to original sources during recall. Across thirteen pre-registered experiments (N = 7,510) and a variety of consumer domains, we investigate the effect of claim objectivity on source memory. We find that source memory is more accurate for opinions than for facts, with no consistent effect on claim recognition memory. We find support for the proposed process by manipulating facts to be more informative about sources and opinions to be less informative about sources. When forming inferences and seeking advice from sources, participants rely more on previously-shared opinions than on previously-shared facts. Our results indicate that opinions are more likely to be accurately attributed to original sources than are facts.