The station was built by the
Midland Railway as simply
Mill Hill in 1868 on its extension to
St. Pancras, being renamed in 1950. The station was rebuilt in the 1960s in connection with the construction of the
M1 motorway. Prior to the
major engineering works to create the
Thameslink Box at , Mill Hill Broadway was also served at peak times by fast trains. These trains provided a non-stop service to twice an hour. In 2009, several morning peak southbound fast services (stopping only at ) and several evening peak northbound fast services (stopping only at West Hampstead Thameslink) were reinstated. From March 2009,
Southeastern and Govia Thameslink Railway began running some peak hour trains from to , though in the off-peak these services turn back at . ==Services==