Fire crews were called to the scene at 6.15am after a lorry caught fire between junctions 32 (Preston) and 31a (Longridge).
Police say the lorry driver escaped unscathed and no injuries have been reported.
A full closure of the southbound carriageway was put in place at 6.50am and was soon followed by the closure of the M55 eastbound between J1 (Preston, Garstang A6) and the M6.
As of 10.30am, there were 60 minute delays on the M6 southbound between J33 and J32 with around 6 miles of congestion.
Similarly, on the M55 eastbound – between J3 (Kirkham, A585) and J1 (Preston) – there were delays of 70 minutes and approximately 6 miles of congestion.
Highways England said the recovery operation was ‘complex’ and warned the motorways could remain closed for some time.