Deployed Service Members Financial Security and Education Act of 2003 - Directs the Secretary of the military department concerned to pay a monthly $1,000 allowance to a member of the armed forces for each month of deployment in the case of a member who is deployed for: (1) 191 consecutive days; or (2) 401 or more of the preceding 730 days.

Amends the Soldiers' and Sailors' Civil Relief Act of 1940 to apply a provision limiting the rate of interest on student loans during a period of military service to all student loans, including loans under Title IV of the Higher Education Act of 1965.

Requires a person in the military service who is enrolled in an institution of higher education at the time of entry into service to be granted a leave of absence from the institution during the period of service and for one year thereafter. Requires such person, after such leave of absence, to be restored to the same educational status (including academic credits, scholarships or grants, and amount of tuition) attained before entry into service. Requires the institution to refund, or provide a credit for, tuition or fees paid for the period covering the leave of absence.