| Competition: | Guy Walmsley & Co Welsh National League |
| Season: | 2011–12 |
| Prevseason: | 2010–11 |
| Nextseason: | 2012–13 |
The 2011–12 Guy Walmsley & Co Welsh National League is the sixty-seventh season of the Welsh National League. The Premier Division began on 12 August 2011 and ended on 17 May 2012. Division One began on 13 August 2011 and ended on 19 May 2012.
| Competition: | Guy Walmsley & Co Welsh National League Premier Division |
| Winners: | FC Cefn |
| Promoted: | FC Cefn |
| Relegated: | Johnstown Youth |
| Biggest Home Win: | Rhydymwyn 10–0 Johnstown Youth 10 March 2012 Gresford Athletic 10–0 Johnstown Youth 1 May 2012 |
| Biggest Away Win: | Johnstown Youth 0–10 FC Cefn 25 February 2012 |
| Highest Scoring: | Llay Welfare 5–8 FC Cefn 17 March 2012 |
| Matches: | 240 |
| Total Goals: | 1004 |
| Competition: | Guy Walmsley & Co Welsh National League Division One |
| Winners: | Saltney Town |
| Promoted: | Saltney Town |
| Biggest Home Win: | Borras Park Albion 15–0 Glyn Ceiriog 10 September 2011 |
| Biggest Away Win: | Hawkesbury Villa 0–12 Saltney Town 31 March 2012 |
| Highest Scoring: | Borras Park Albion 15–0 Glyn Ceiriog 10 September 2011 |
| Matches: | 155 |
| Total Goals: | 778 |