Investor in Iran Accountability Act of 2005

Investor in Iran Accountability Act of 2005 - States that it is U.S. policy to: (1) enforce existing U.S. economic sanctions against Iran, including sanctions imposed under the Iran and Libya Sanctions Act of 1996 on persons who make certain investments that contribute to Iran's ability to develop its petroleum and natural gas resources; (2) make available to the public information regarding a U.S. or U.S.-controlled person who maintains any energy sector investment in Iran; and (3) seek international cooperation in enforcing economic sanctions against Iran and in prohibiting any investment in Iran until Iran ceases to support international terrorism.

Directs the Secretary of the Treasury to publish and update in the Federal Register, and make available on the Department of the Treasury's website, lists of specified U.S. or U.S.-controlled persons, foreign persons, investment companies, and pension plans that maintain investments in the Iranian energy sector.

Directs the President to undertake negotiations with the government of a foreign country to prohibit any investment in the Iranian energy sector by any person controlled by that foreign country.

Extends the Iran and Libya Sanctions Act of 1996.