Secure Government Buildings from Espionage Act of 2019 This bill instructs the General Services Administration, the Architect of the Capitol, or any other federal agency (other than the Department of Defense), before entering into a lease agreement with a public or private entity to accommodate a federal agency in a building or other improvement that will be used for high-security leased space, to require such entity to identify each beneficial owner of such entity; to disclose to such agency any beneficial owner that is a foreign person; and if such agency is assigning the building or other improvement to a federal tenant, to notify that tenant of any such disclosure. The agency shall require such entity to provide such identification and disclosure when first submitting a proposal in response to an agency solicitation, and update such information within 60 days of any change in the beneficial owners of that entity or the information required to be provided relating to each such owner.