"Fair dealing" and "fair use" are related concepts pertaining to users' rights under copyright law. It is nevertheless important to understand that fair dealing and fair use are not synonymous terms since their meaning and scope are defined by different legal systems. It is challenging to adequately summarize the shared and divergent underpinnings of fair dealing and fair use succinctly, given their highly complex and contested nature. The following brief comparison aims merely to sketch a broad picture of some of the basic similarities and differences between fair dealing and fair use.

Fair dealing is an exception to copyright infringement laid out in the copyright statutes of common law jurisdictions such as Great Britain, Canada, Australia and New Zealand. The copyright acts of these jurisdictions provide that fair dealing with a copyrighted work is not infringing if the dealing is for a fair dealing purpose specifically stated in the act. This means, for example, that if a work is copied for a purpose other than one or more of the statutory fair dealing purposes, the copying cannot be a fair dealing regardless of the copier's possibly beneficial or meritorious goal.

Fair use is a limitation on exclusive rights in works of authorship granted under U.S. copyright law. Like the Canadian Copyright Act's fair dealing provision, Title 17 of the United States Code states that fair use of a copyrighted work is not an infringement of copyright. But unlike the Canadian statute, Title 17 provides an open-ended list of purposes that may be fair use - "purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use)..." - instead of listing a finite list of purposes defining the bounds of acts that may be fair dealing.

Another point of divergence is the availability of statutory guidance on how the fairness of a dealing or use should be evaluated. Since fair dealing provisions generally lack statutory definitions or regulations specifying how fairness is to be determined, the appropriate approach to assessing the fairness of actual dealings with protected works is a matter for the courts to decide. In CCH, the Supreme Court of Canada set out a two-step analytical framework to assess fair dealing in which the second step identifies six fairness factors. The Court said the extent to which the factors are relevant may vary from case to case and noted some cases may require consideration of factors beyond the six identified in the framework.

In contrast, the fair use provision in U.S. copyright law prescribes four factors that must be included in a fairness determination: the 1) purpose and character of the use, 2) nature of the copyrighted work, 3) amount and substantiality of the portion of the work used and 4) effect of the use on the potential market or value of the work. These fair use factors are similar to the six CCH fair dealing factors (purpose, character, amount, and effect of the dealing, nature of the work, and alternatives to the dealing) but U.S. and Canadian case law have applied the fairness factors in different ways.

The following sources provide more in-depth comparative discussions of fair dealing and fair use: