| 1965–66 Lancashire Cup | |
| Structure: | Regional knockout championship |
| Season Champs: | Warrington |
| Season Champ Name: | Winners |
| Runner-Up Name: | Runner-up |
| Second Place: | Rochdale Hornets |
| Prevseason Link: | 1964 Lancashire Cup |
| Prevseason Year: | 1964–65 |
| Nextseason Link: | 1966 Lancashire Cup |
| Nextseason Year: | 1966–67 |
| No Of Teams: | 14 |
1965–66 was the fifty-third occasion on which the Lancashire Cup completion had been held.
Warrington won the trophy by beating Rochdale Hornets by the score of 16-5
The match was played at Knowsley Road, Eccleston, St Helens, Merseyside, (historically in the county of Lancashire). The attendance was 21,360 and receipts were £3,800
It would be almost another 20 years before the attendance would again exceed 20,000
The total number of teams entering the competition remained the same at 14.
The same fixture format was retained, and due to the number of clubs this resulted in no bye but one “blank” or “dummy” fixture in the first round, and one bye in the second round
Involved 7 matches (with no bye but one “blank” fixture) and 14 clubs
| width=20 abbr="No" | Game No | width=100 abbr="Date" | Fixture date | width=150 abbr="Home team" | Home team | width=5 abbr="space" | width=20 abbr="Score" | Score | width=5 abbr="space" | width=150 abbr="Away team" | Away team | width=150 abbr="Venue" | Venue | width=30 abbr="Att" | Att | width=30 abbr="Rec" | Rec | width=20 abbr="Notes" | Notes | width=30 abbr="Ref" | Ref | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Fri 10 Sep 1965 | St. Helens | 7-8 | Swinton | Knowsley Road | 14,500 | [2] | ||||||||||||||||
| 2 | Sat 11 Sep 1965 | Blackpool Borough | 9-14 | Rochdale Hornets | Borough Park | ||||||||||||||||||
| 3 | Sat 11 Sep 1965 | Leigh | 21-7 | Liverpool City | Hilton Park | ||||||||||||||||||
| 4 | Sat 11 Sep 1965 | Oldham | 21-14 | Barrow | Watersheddings | ||||||||||||||||||
| 5 | Sat 11 Sep 1965 | Salford | 14-5 | Workington Town | The Willows | ||||||||||||||||||
| 6 | Sat 11 Sep 1965 | Widnes | 9-12 | Warrington | Naughton Park | [3] [4] | |||||||||||||||||
| 7 | Sat 11 Sep 1965 | Wigan | 25-23 | Whitehaven | Central Park | [5] | |||||||||||||||||
| 8 | blank | blank |
Involved 3 matches (with one bye) and 7 clubs
| width=20 abbr="No" | Game No | width=100 abbr="Date" | Fixture date | width=150 abbr="Home team" | Home team | width=5 abbr="space" | width=20 abbr="Score" | Score | width=5 abbr="space" | width=150 abbr="Away team" | Away team | width=150 abbr="Venue" | Venue | width=30 abbr="Att" | Att | width=30 abbr="Rec" | Rec | width=20 abbr="Notes" | Notes | width=30 abbr="Ref" | Ref | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Wed 15 Sep 1965 | Rochdale Hornets | 4-0 | Swinton | Athletic Grounds | ||||||||||||||||||
| 2 | Wed 15 Sep 1965 | Salford | 5-8 | Leigh | The Willows | ||||||||||||||||||
| 3 | Thu '16 Sep 1965 | Oldham | 28-13 | Wigan | Watersheddings | ||||||||||||||||||
| 4 | Warrington | bye |
Involved 2 matches and 4 clubs
| width=20 abbr="No" | Game No | width=100 abbr="Date" | Fixture date | width=150 abbr="Home team" | Home team | width=5 abbr="space" | width=20 abbr="Score" | Score | width=5 abbr="space" | width=150 abbr="Away team" | Away team | width=150 abbr="Venue" | Venue | width=30 abbr="Att" | Att | width=30 abbr="Rec" | Rec | width=20 abbr="Notes" | Notes | width=30 abbr="Ref" | Ref | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Thu 23 Sep 1965 | Rochdale Hornets | 19-0 | Leigh | Athletic Grounds | ||||||||||||||||||
| 2 | Wed 06 Oct 1965 | Warrington | 21-10 | Oldham | Wilderspool |
| width=20 abbr="No" | Game No | width=100 abbr="Date" | Fixture date | width=150 abbr="Home team" | Home team | width=5 abbr="space" | width=20 abbr="Score" | Score | width=5 abbr="space" | width=150 abbr="Away team" | Away team | width=150 abbr="Venue" | Venue | width=45 abbr="Att" | Att | width=60 abbr="Rec" | Rec | width=20 abbr="Notes" | Notes | width=30 abbr="Ref" | Ref | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Friday 29 October 1965 | Warrington | 16-5 | Rochdale Hornets | Knowsley Road | 21,360 | £3,800 | 1 | [6] |
1 * 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