The ten-vehicle collision occurred between junctions 32 (Broughton) and 33 (Hampson Green) at around 11.20am on Wednesday.
The northbound carriageway reopened at around 4am on Thursday, but lane three remained closed for emergency barrier repairs.
At 12.25pm, National Highways confirmed the southbound carriageway had also reopened with lane three closed.
These were the scenes after the motorway reopened:
1. The M6 near Lancaster has reopened following yesterday's fatal crash
A lorry travelling northbound smashed through the central reservation before crashing into several other vehicles and overturning. | Kelvin Lister-Stuttard
2. The M6 near Lancaster has reopened following yesterday's fatal crash
The lorry driver, a man in his 50s, sadly died at the scene. | Kelvin Lister-Stuttard
3. The M6 near Lancaster has reopened following yesterday's fatal crash
The driver of a Ford Transit, a man in his 40s, and the driver of a Suzuki Swift, a woman in her 40s, also suffered “serious injuries”. | Kelvin Lister-Stuttard
4. The M6 near Lancaster has reopened following yesterday's fatal crash
Three other people suffered “more minor injuries” in the crash. | Kelvin Lister-Stuttard