A child was critically injured while riding in a car with his parents and two siblings yesterday when a drugged-out driver hit the family’s pickup truck on Sunrise Highway on Long Island, Suffolk police said.

The 5-year-old boy was airlifted to Stony Brook University Medical Center after Steven Kinalis rammed his 2007 Toyota Scion into the back of a 2004 Dodge truck driven by the boy’s father, cops said.

Kevin Gaffney, 36, his wife, 7-year-old daughter and 2-year-old son were also taken to Stony Brook after the 9:40 a.m. crash in Shirley, which sent the family vehicle into a tree.

The impact was so strong that the car partially crumpled.

Kinalis was arrested on a charge of driving while impaired by drugs.

A third injured person was taken to Brookhaven Memorial Hospital Medical Center, but authorities declined to release exact information about the nature of the remaining victims’ injuries.