| Official Name: | Suan Yai Subdistrict |
| Native Name: | Thai: ตำบลสวนใหญ่ |
| Settlement Type: | Subdistrict |
| Subdivision Type: | Country |
| Subdivision Type2: | Province |
| Subdivision Name2: | Nonthaburi |
| Subdivision Type3: | District |
| Subdivision Name3: | Mueang Nonthaburi |
| Area Total Km2: | 2.5 |
| Area Footnotes: | [1] |
| Population As Of: | 2020 |
| Population Footnotes: | [2] |
| Population Total: | 33706 |
| Population Density Km2: | 13482.4 |
| Timezone: | ICT |
| Utc Offset: | +7 |
| Postal Code Type: | Postal code |
| Blank Name: | TIS 1099 |
Suan Yai (Thai: สวนใหญ่, in Thai pronounced as /sǔa̯n jàj/) is one of the ten subdistricts (tambon) of Mueang Nonthaburi District, in Nonthaburi Province, Thailand. The subdistrict is bounded by (clockwise from north) Bang Kraso, Talat Khwan, Bang Khen, Wong Sawang, and across the Chao Phraya River, Bang Kruai, Bang Phai, Bang Si Mueang and Sai Ma subdistricts. The whole area of the subdistrict is covered by Nonthaburi City Municipality (Thai: เทศบาลนครนนทบุรี).[1] In 2020 it had a total population of 33,706 people.[2]