Cambodia Accountability and Return on Investment Act of 2019 This bill imposes conditions for assistance to Cambodia and contains other provisions related to democracy in Cambodia. No funds authorized for assistance to Cambodia may be made available unless the Department of State certifies to Congress that Cambodia has taken certain actions, including (1) strengthening regional security and stability, in particular in relation to the South China Sea and by enforcing sanctions against North Korea; (2) protecting its sovereignty from interference from China; and (3) respecting constitutionally protected rights and releasing political prisoners. Various other benefits, such as Cambodia's designation as a beneficiary developing country for trade treatment purposes, shall also be suspended until such a certification is made. The State Department shall report to Congress on the implementation of existing visa-blocking restrictions against individuals involved in undermining democracy in Cambodia. The President shall take all actions necessary to direct U.S. financial institutions to promptly report to the Office of Foreign Assets Control as to holdings, transfers, or interests in property belonging to individuals involved in undermining democracy in Cambodia. The President may impose property-blocking sanctions on such individuals. The bill authorizes the broadcast of Khmer-language internet content to inform the Cambodian people of various topics, such as China's undermining of Cambodia's sovereignty.