The incident happened at around 9.30am on Tuesday (May 23), British Transport Police confimed.
The scene was attended by the force alongside Metropolitan Police officers from Harrow, the London Fire Brigade and paramedics from the London Ambulance Service.
Police are working to identify the victim and inform the next of kin.
The station was shut after the incident, with London Underground services on the Metropolitan and Piccadilly Lines severely affected.
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