Ontario Provincial Police say a total of 343 people died on provincial roads in 2017, marking a five-year high.
By comparison, there were 307 deaths in 2016.
In a news release issued Monday, the OPP said that the fatalities were partially due to the increase in driver inattentiveness, speed, and not wearing seatbelts.
"The OPP is saddened and disappointed to see 2017 mark one of the worst years in recent history for fatalities on and off the road,” OPP Commissioner J.V.N. Vince Hawkes said in a statement.
“As is the case every year, the majority of these deaths were preventable and attributed to poor driving behaviours. Until all drivers respect and observe road, off-road and marine laws that are designed to keep us all safe, these tragic deaths will continue".
In total, the OPP responded to 68,794 collisions last year compared to 67,450 in 2016. The list of fatalities included 48 motorcyclists and 27 pedestrians. Ninety-one people died in 76 collisions involving commercial transport trucks.
Snowmobile fatalities reached an all-time high in 2017 with 29 deaths, mostly due to excessive speed, loss of control, and driver inattention.
Boating fatalities reached an eight-year-high with 31 deaths in 2017. The OPP attributed the majority of these deaths to lack of life jackets.
A total of 22 people died in off-road vehicle incidents in 2017. About half of those who died over the last two years did not wear a helmet, the OPP said.
