Relativism about truth is the broadest and strongest form of relativism available, for the various versions of local relativism, for instance relativism in the epistemic, moral, aesthetic domains, can be restated as a claim about the relativity of truth in those domains. Alethic relativism is often contrasted with a host of positions including objectivism, universalism, and realism about truth. Relativism about truth is a doctrine almost as old as philosophy itself, which has made a stunning comeback in philosophical debate. Historically, at least since Plato, the charge of self-refutation and infinite regress has been the most trenchant criticism of relativism. The truth-relativists’ main strength over classical relativists is that they are prima facie able to preserve both the apparent subjectivity of taste discourse and our intuition that exchanges in that domain may constitute genuine disagreements. The chapter examines the most general and strongest form of relativism, alethic relativism, or relativism about truth.