Police said the incident took place on Kuti Road in Bhopura.
Four people - a mother and her three children - died in the blaze in the hutment.
Those killed were identified as Rajo Devi (36), the mother, Manisha (14), Nakul (8) and Bhim (7). They all originally belonged to Bihar and were living with two male members.
"It took about about an hour to control the fire and a dozen fire tenders were pressed into service...prima facie it seems an accidental fire," said Ghaziabad Superintendent of Police Shiv Hari Meena.