The 1991 All England Open was the 81st edition of the All England Open Badminton Championships. It was held from March 20 to March 24, 1991, in London, England.
It was a five-star tournament and the prize money was US$125,000.
| Category | Winners | Runners-up | Score |
|---|---|---|---|
| Men's singles | Ardy Wiranata | Foo Kok Keong | 15–12, 15–10 |
| Women's singles | Susi Susanti | Sarwendah Kusumawardhani | 0–11, 11–2, 11–6 |
| Men's doubles | Li Yongbo & Tian Bingyi | Kim Moon-soo & Park Joo-bong | 12–15, 15–7, 15–8 |
| Women's doubles | Chung So-young & Hwang Hye-young | Kimiko Jinnai & Hisako Mori | 15–5, 15–3 |
| Mixed doubles | Park Joo-bong & Chung Myung-hee | Thomas Lund & Pernille Dupont | 15–10, 10–15, 15–4 |
| Preceded by 1990 All England |
All England Open Badminton Championships | Succeeded by 1992 All England |