The No Child Left Behind Act (NCLB) is the name given to the 2001 reauthorization of the Elementary and Secondary Education Act (ESEA) passed by the U.S. Congress. NCLB represents the federal government’s deepest foray into public education in the United States as it mandated standardized testing of students, consequences for underperforming schools, and minimum standards for teachers. While overwhelmingly passed in both houses of Congress and lauded by many, the law was also highly criticized for some of its provisions, including setting unreasonable performance targets and an overreliance on standardized tests. Research has shown improvements in student achievement since NCLB, but its provisions have also produced many unintended consequences, including a narrowing of curricular offerings and cheating scandals. This entry provides an overview of ...