| State: | MS |
| Type: | MS |
| Route: | 321 |
| Maint: | MDOT and Quitman County |
| Map Custom: | yes |
| Established: | 1956 |
| Length Mi1: | 5.916 |
| Length Ref1: | [1] |
| Direction A1: | South |
| Terminus A1: | near Webb |
| Direction B1: | North |
| Terminus B1: | Brazil Quitman County Road in Brazil |
| Length Mi2: | 3.215 |
| Direction A2: | South |
| Terminus A2: | Anderson Road / Schieleville Road near Lambert |
| Direction B2: | North |
| Terminus B2: | in Lambert |
| Counties: | Tallahatchie, Quitman |
| Previous Type: | MS |
| Previous Route: | 316 |
| Next Type: | MS |
| Next Route: | 322 |
Mississippi Highway 321 (MS 321) is a state highway consisting of two segments, one connecting Webb to Brazil in Tallahatchie County, the other in Quitman County in and around Lambert. It is a two-lane road for its entire length.
The southern segment of MS 321 begins about 1miles east of Webb along MS 32 and Pecan Road. The two-lane state maintained highway[2] heads north eventually paralleling the Tallahatchie River. The road is otherwise surrounded by agricultural fields. In the unincorporated community of Brazil, state maintenance ends before the road, continuing north as Brazil Quitman County Road, crosses Buzzard Bayou.
The northern segment of MS 321, completely maintained by Quitman County and the town of Lambert,[2] begins at the intersection of Anderson Road and Schieleville Road. The intersection is located near the former Camp B of the Mississippi State Penitentiary, now mostly the O'Keefe Wildlife Management Area. The road heads due north paralleling a railroad and traveling through farmland before the road enters the town of Lambert. In the town, MS 321 carries the name 6th Street and passes by houses and churches. MS 321 ends at an intersection with MS 322 in Lambert.