The man, aged in his 80s, drove a silver Ford Focus southbound on the northbound carriageway at Tebay Services at around 4pm yesterday (Wednesday, November 3).
Police say his car then struck an oncoming BMW, Audi and a Scania car transporter.
The crash closed the southbound M6 and two lanes of the northbound carriageway for around an hour whilst emergency services attended.
The pensioner was taken to Royal Lancaster Infirmary as a precaution, say Cumbria Police. The other drivers suffered minor injuries.
A spokesman for Cumbria Police said: "Police were called at around 4pm on Wednesday (November 3) to the report of a vehicle travelling southbound on the M6 northbound at Tebay services.
"The vehicle was a silver Ford Focus. It was further reported the vehicle was in collision with three other vehicles a BMW, Audi and a Scania car transporter.
"The driver of the Ford a man in his 80s was taken to the Royal Lancaster infirmary as a precaution. The other drivers suffered minor injuries."
Anyone with information relating to this incident can call police on 101, quoting incident number 153 of November 3.
Alternatively, information can be reported to Crimestoppers, anonymously, on 0800 555 111.