| San Pier d'Isonzo | |
| Official Name: | Comune di San Pier d'Isonzo |
| Coordinates: | 45.85°N 41°W |
| Region: | Friuli-Venezia Giulia |
| Province: | Gorizia (GO) |
| Frazioni: | Cassegliano, San Zanut[1] |
| Mayor: | Claudio Bignolin (since 2021)[2] |
| Area Total Km2: | 9 |
| Population Footnotes: | [3] |
| Population Total: | 1936 |
| Population As Of: | 2024 |
| Elevation M: | 18 |
| Saint: | Sts. Peter and Paul |
| Postal Code: | 34070 |
| Area Code: | 0481 |
San Pier d'Isonzo (Bisiacco: San Piero; Friulian: San Pieri dai Bisiacs) is a town and Italian: [[comune]] (municipality) in the Regional decentralization entity of Gorizia, Friuli-Venezia Giulia, northeast Italy. It borders Turriaco. The village first appears in a patriarchal document in 1247.[4]