The "Fighting Budget Waste Act" amends title 31, United States Code, to require the President and the Director of the Office of Management and Budget (OMB) to consider the most recent Government Accountability Office (GAO) report when preparing the annual federal budget. This GAO report identifies opportunities to reduce fragmentation, overlap, and duplication within government operations, aiming to improve efficiency and effectiveness. The legislation further mandates that, concurrently with the budget submission to Congress, the OMB Director must provide a separate report. This accompanying report will detail the OMB's specific findings regarding the GAO's recommendations. The bill's purpose is to formally integrate expert analysis on reducing waste and enhancing government performance into the federal budget planning and accountability process.