Stop Sexual Harassment in K-12 Act This bill outlines the role and duties of Title IX coordinators in elementary and secondary schools, including by requiring local educational agencies to increase the number of full-time employees designated to serve as a Title IX coordinator per specified student population. The bill also creates a grant program to train teachers and staff on how to respond to signs of sex-based harassment and assault of students and requires the Department of Education to develop a sex-based harassment survey.