Closing the Foreign Lobbying Loophole Act - Amends the Foreign Agents Registration Act of 1938 to repeal the exemption of agents of foreign principals from mandatory registration with the Attorney General if they are already registered under the Lobbying Disclosure Act.
Redefines "agent of a foreign principal" to extend its meaning to agents who through any other person outside the United States represents the interests of a foreign principal before any agency or official of the federal government.