Emergency services responded to Devonshire Street in Surry Hills at around 1.15pm when the man was struck and became trapped beneath the carriage.
The man, believed to be in his 40s, was treated by NSW Ambulance paramedics but he died at the scene.
He is yet to be formally identified.
Police established a crime scene and an investigation into the cause of the incident has commenced.
A report will be prepared for the information of the coroner.
The incident has impacted some light rail services in the city, according to a Transport for NSW spokesperson.
“L2 and L3 light rail services are unavailable between Moore Park and Circular Quay due to a situation necessitating emergency services at Surry Hills,” the representative explained.
“Replacement buses have been requested between Central and Moore Park but are not yet running.
“Passengers can consider taking regular route buses between the city and Moore Park, or trains between Central and Circular Quay. L2 and L3 light rail services remain operational between Moore Park and Randwick, and between Moore Park and Juniors Kingsford.
“Passengers are advised to allow plenty of extra travel time, and can check information displays at stops for service updates.”
