Transparency in Classification Act of 2020 This bill establishes the Interagency Security Classification Appeals Panel, a body to review decisions related to the classification of information, and contains other related provisions. The appeals panel shall provide the public and authorized users of the classification system with a forum to request review of agency classification decisions. It shall also provide members of Congress a mechanism for expedited reviews of classification decisions. Each agency that handles classified information shall establish a policy for an individual authorized to access classified information to request a review of a classification decision. Such an individual may also appeal a classification decision to the appeals panel. Appeals panel decisions may be appealed to the President. The bill imposes various requirements related to the appeals processes created under this bill, including time lines for rendering decisions. The appeals panel shall establish a public website with information about all appeals requests that it has received.