There are quite a few! The biggest one is WCAG 2.0, the standard guidelines for accessibility compliance: https://www.w3.org/TR/WCAG20/
That can be a bit hard to digest, though, so there are additional tools that may help. I work on aXe, an accessibility auditing tool that includes browser extensions and various APIs. aXe can audit any local or remote webpage and provide you with a list of issues that map to WCAG success criteria and best practices.