Seven people died and more than 60 people were injured when a tram overturned near Sandilands just before the morning rush hour.
A ceremony will take place at the public memorial in New Addington at 11 o’clock.
It will include a reading of the names of those who died, followed by a period of silence and the laying of floral tributes.
Jean Smith lost her 35-year-old son Mark in the derailment.
