Watford have played Merthyr Town 21 times in competitive football, winning 11, drawing 4 and losing 6, first meeting on 9 Oct 1920 and most recently on 26 Dec 1929. Every meeting is listed below.
| Date | Season | Competition | Venue | Opponent | Score | Scorers | Att |
|---|---|---|---|---|---|---|---|
| 9 Oct 1920 | 1920–21 | Third Division | A | Merthyr Town | 0–2 | ||
| 16 Oct 1920 | 1920–21 | Third Division | H | Merthyr Town | 1–0 | ||
| 18 Feb 1922 | 1921–22 | Third Division South | H | Merthyr Town | 4–1 | ||
| 25 Feb 1922 | 1921–22 | Third Division South | A | Merthyr Town | 2–1 | ||
| 7 Oct 1922 | 1922–23 | Third Division South | A | Merthyr Town | 3–2 | ||
| 14 Oct 1922 | 1922–23 | Third Division South | H | Merthyr Town | 1–1 | ||
| 20 Oct 1923 | 1923–24 | Third Division South | H | Merthyr Town | 4–0 | ||
| 27 Oct 1923 | 1923–24 | Third Division South | A | Merthyr Town | 1–2 | ||
| 10 Apr 1925 | 1924–25 | Third Division South | H | Merthyr Town | 3–1 | ||
| 14 Apr 1925 | 1924–25 | Third Division South | A | Merthyr Town | 1–0 | ||
| 31 Oct 1925 | 1925–26 | Third Division South | A | Merthyr Town | 1–4 | ||
| 13 Mar 1926 | 1925–26 | Third Division South | H | Merthyr Town | 6–1 | ||
| 13 Nov 1926 | 1926–27 | Third Division South | H | Merthyr Town | 4–1 | ||
| 2 Apr 1927 | 1926–27 | Third Division South | A | Merthyr Town | 1–1 | ||
| 9 Apr 1928 | 1927–28 | Third Division South | H | Merthyr Town | 1–1 | ||
| 10 Apr 1928 | 1927–28 | Third Division South | A | Merthyr Town | 1–3 | ||
| 10 Nov 1928 | 1928–29 | Third Division South | A | Merthyr Town | 1–2 | ||
| 8 Dec 1928 | 1928–29 | FA Cup | H | Merthyr Town | 2–0 | ||
| 23 Mar 1929 | 1928–29 | Third Division South | H | Merthyr Town | 4–0 | ||
| 25 Dec 1929 | 1929–30 | Third Division South | A | Merthyr Town | 2–2 | ||
| 26 Dec 1929 | 1929–30 | Third Division South | H | Merthyr Town | 2–3 |