The No Child Left Behind Act of 2001 (N.C.L.B.) is a United States Act of Congress that is a re-authorization of the Elementary and Secondary Education Act, which included Title I, the government's flagship aid program for disadvantaged students. N.C.L.B. supports standards-based education reform based on the premise that setting high standards and establishing measurable goals can improve individual outcomes in education.

The Act requires states to develop assessments in basic skills. To receive federal school funding, States must give these assessments to all students at select grade levels. The Act does not assert a national achievement standard. Each individual state develops its own standards. N.C.L.B. expanded the federal role in public education through annual testing, annual academic progress, report cards, teacher qualifications, and funding changes. The bill passed in the U.S. Congress with bipartisan support.