Milton District High School (MDHS) is a public secondary school located in Milton, Ontario, Canada. MDHS is part of the Halton District School Board, and educates approximately 1700 students.

Prior to Milton district high school's (second) opening in 1967, Students had attended the old Milton district high school on Martin street . When the new high school opened, grade 10 to 12 students were transferred there, and Martin Street School [1] became a high school, serving students in grade 9 only. MDHS remained the only secondary school in Milton until E.C. Drury High Schoolopened in 1980 (but is now for def students only), followed by Bishop Reding Catholic Secondary School in 1986.