| State: | NM |
| Type: | SR |
| Route: | 373 |
| Alternate Name: | West Union Avenue |
| Map Custom: | yes |
| Length Mi: | 1.496 |
| Length Ref: | [1] |
| History: | Truncated in 1992 |
| Direction A: | West |
| Junction: | on border of Mesilla |
| Direction B: | East |
| Terminus B: | McDowell Road on border of Mesilla |
| Previous Type: | NM |
| Previous Route: | 372 |
| Next Type: | NM |
| Next Route: | 374 |
State Road 373 (NM 373), also known as West Union Avenue, is a 1.496miles state highway on the southern border of Mesilla in Doña Ana County, New Mexico, United States, that connects New Mexico State Road 372 (NM 372) with the southern end of McDowell Road.
NM 373 was truncated to its current eastern terminus on November 2, 1992 in a road exchange agreement with the city of Mesilla.[1]