Police said two-and-half-year-old Yadu Krishnan was killed when panic stricken people ran for safety on seeing the angry elephant. At least 25 devotees were injured in the melee.
All the injured have been admitted to nearby hospitals.
Today was the last day of the annual festival and a large number of people had gathered at the temple.
Police said the elephant Kannan suddenly ran amok as it was being taken for the festival and waived its tusk hurting people nearby including a police sub-inspector. It started running and two other elephants standing nearby also ran.
In the confusion that prevailed, there was a stampede as panic-stricken people ran for safety.
The baby boy, who was with his grandmother, fell down and was killed in the melee, police said.
The grandmother suffered serious injuries and has been hospitalised.
All the elephants were brought under control by its mahouts.
About four years ago, an elephant belonging to the temple had ran amok killing three persons.
