The force said the 35-year-old man was pronounced dead at the scene of the incident.
The force is appealing for anyone with information about what happened to contact them.
It comes after a black Citroen Berlingo van, a silver Seat Leon car and a white Vauxhall Crossland were all involved in a collision on the A726 Queensway in East Kilbride.
The incident happened on the eastbound side of the road, near to a roundabout on Murrayhill and Cornwall Street, shortly after 6.30pm on Wednesday December 7.
No one in any of the vehicles was injured.
The road was closed for around six hours for investigations to take place with Sergeant Gemma Blackadder, of the road policing unit, in Motherwell stating: “Our thoughts are with the man’s family and friends at this difficult time.
“Our inquiries to establish the full circumstances which led to this incident are ongoing and I would urge anyone with information to get in touch.
“We would also be keen to speak to anyone who may have dashcam footage from the area.”