If you wanted to build the perfect purveyor of knowledge, you would do well to avoid human beings. They are too error prone. They are, more often than not, defective inquirers. They have limited attention spans, limited cognitive processing powers, unreliable and inefficient memories, inherently flawed intellectual characters, and pedestrian interpersonal and intrapersonal skills. They are flawed listeners. They are at times dogmatic and prejudicial reasoners. Too often they cannot get out of their own way – life, work, character flaws, relationships; indeed, the trappings of being human in a socially oriented split‐attention environment strip them of being the very best version of themselves. More often than not, we are less than we ought to be. Enter vice epistemology. Theorists in this field seek to foreground the value of better understanding epistemic vices that obstruct knowledge acquisition, sharing, auditing, and production. Rather than focus on knowledge acquired via strictly controlled laboratory conditions, vice epistemologists seek to better understand the nature, scope, identity, and significance of intellectual character traits, attitudes, and ways of thinking, which systematically, though not invariably, block the path to knowledge. Contra virtue epistemologists who spend a great deal of time untangling how prototypical virtuous thinkers under ideal conditions should think, vice epistemologists look to more fully understand how, on balance, imperfect people, with imperfect cognition, in a contested fact‐value world, actually think, reason, question, inquire, generate inferences, handle evidence, and so on. This entry surveys epistemic vices, in particular how they corrupt knowledge acquisition, auditing, and sharing.