Preventing Sexual Abuse of K-12 Students Act of 2021 This bill requires sexual abuse awareness training in elementary and secondary schools. Specifically, the bill requires states receiving federal elementary and secondary education funds to establish and implement a statewide policy requiring each local educational agency to (1) develop codes of conduct to prevent sexual abuse of students by identifying acceptable and unacceptable behavior for school personnel and students; and (2) ensure that school personnel receive specified training, including training on sexual abuse and misconduct awareness and prevention. In addition, the bill expands the allowable uses for certain grants (e.g., Student Support and Academic Enrichment grants) to include sexual abuse awareness training. Finally, the Department of Education must make recommendations to Congress for preventing the sexual abuse of elementary and secondary school students.