The 1986–87 Lancashire Cup, known as the Grunhalle Lager Lancashire Cup for sponsorship reasons, was the 74th occasion on which the Lancashire Cup competition had been held.

Wigan won the trophy by beating Oldham by the score of 27-6. The match was played at Knowsley Road, Eccleston, St Helens, Merseyside, (historically in the county of Lancashire). The attendance was 20,180 and receipts were £60,329.

This was Wigan’s third appearance in three years and a second victory in what would a run of four victories and five appearances in five successive years.
The attendance was again at a very pleasing level, the third of the five year period when it would reach around the 20,000 level, and the receipts reached a new near record level

This season the total number of entrants remained at the 16 level.
With this full sixteen members there was no need for “blank” or “dummy” fixtures or any byes.

^[1][2]

1 * A record score for a match in this competition and a record defeat for Carlisle in any competition
2 * Knowsley Road was the home ground of St. Helens from 1890 to 2010. The final capacity was in the region of 18,000, although the actual record attendance was 35,695, set on 26 December 1949, for a league game between St Helens and Wigan

• 1986–87 Rugby Football League season
• Rugby league county cups