1899–1900 Northern Rugby Football Union season

The Lancashire Senior Competition was won by Runcorn (from Cheshire) and the Yorkshire Senior Competition by Bradford.[1]

Hull Kingston Rovers played their first season in the Northern Rugby Union this season. Their first match away at Bradford on 2 September ended in a 3-0 defeat.[2]

Millom replaced Morecambe. Although participating in the Lancashire Senior Competition, Runcorn and Stockport were from Cheshire, and Millom were from Cumberland. Runcorn won the competition and Tyldesley were relegated after finishing bottom of the league and losing the promotion/relegation match 22–8 to Barrow.[3]

	Team	Pld	W	D	L	PF	PA	Pts
1	Runcorn	26	22	2	2	232	33	46
2	Oldham	26	21	1	4	343	75	43
3	Swinton	26	19	1	6	210	108	39
4	St. Helens	26	16	3	7	207	119	35
5	Widnes	26	12	4	10	174	146	28
6	Warrington	26	12	1	13	174	128	25
7	Broughton Rangers	26	13	1	12	132	138	25[lower-alpha 1]
8	Salford	26	12	0	14	196	176	24
9	Stockport	26	10	2	14	126	136	22
10	Leigh	26	8	5	13	119	211	21
11	Rochdale Hornets	26	9	1	16	90	181	17[lower-alpha 1]
12	Millom	26	7	1	18	112	234	15
13	Wigan	26	7	1	18	70	230	15
14	Tyldesley	26	2	1	23	66	336	5

Bradford won the competition. There was no promotion or relegation as Liversedge won the promotion/relegation test match against Heckmondwike 11–2.[3]

Swinton beat Salford 16-8 in the Challenge Cup Final at Fallowfield Stadium, Manchester played before a crowd of 17,864.[4]