International & Naturalized Citizens
The University of Maryland database is an excellent list of fellowships with no U.S. citizenship requirement.
International students with green cards are eligible for many fellowships offered by US-based organizations and foundations. Those who are not green card holders are not eligible for most of these. Exceptions include Jack Kent Cooke undergraduate and graduate scholarships, Watson Fellowships, certain Ford Foundation awards, and Howard Hughes Medical Institute Predoctoral Fellowships. Applications are accepted for Rotary Ambassadorial Scholarships from citizens of all countries with Rotary Clubs, which covers most of the world. Gates Cambridge Scholarships offer world-wide eligibility except in the UK; Rhodes Scholarships invite applications from all Commonwealth countries. Citizens of EU nations and the UK are eligible for certain awards for study in those countries. Check professional associations in your field of study both here and abroad, nationality-based organizations in the U.S. (example: the Korean American Scholarship Foundation), and sources in your home country. Also see links on fellowships pages at Yale University and the University of Maryland's web. There are several fellowships specifically for international women, including the Margaret McNamara Memorial Fund, AAUW fellowships, and P.E.O. international awards.