"After careful deliberation, we have determined we will not grant this type of exemption as it will pose a road safety risk," Wynne was quoted as saying in a letter.
"Ultimately, the safety of Ontarians is my utmost priority, and I cannot justify setting that concern aside on this issue," Wynne said.
Wynne said safety trumps religious freedoms in this case. There are nearly 2 Lakh Sikhs living in Ontario.
"As you know, the issue of balance between religious accommodation and public safety has been considered by the courts in Ontario which, on this issue, have found that Ontario's mandatory helmet law does not infringe on the Charter of Rights and Freedoms, nor the Ontario Human Rights Code," she said.
The group for almost four years been demanding exemption for Sikh riders on religious grounds, Manohar Singh Bal, secretary of the Canadian Sikh Association, was quoted as saying by the Toronto Star.
Jagmeet Singh, Member of Provincial Parliament of the New Democratic Party said he was "deeply disappointed by Wynne's decision not to grant exemption to motorcycle helmet laws for turbaned Sikhs".