The Northern Indiana Valley Conference was an Indiana High School Athletic Association sanctioned conference in the South Bend/Mishawaka metropolitan area. The conference began as the St. Joseph County Conference in 1932, made up of county schools and South Bend schools not in the Northern Indiana Conference. Smaller county schools consolidated and moved to different conferences with schools of similar size, and by 1966 the county league was down to four members. The league decided to take in the two county Catholic schools, Marian and St. Joseph the next year, and rebranded as the Northern Indiana Valley Conference. The league took a hard hits beginning in 1974. Clay became an Independent (until 1978). Penn was accepted into the Northern Indiana Athletic Conference, South Bend Jackson announced its closure after the school year, and the league stopped sponsoring football. South Bend LaSalle were invited to replace LaPorte in the Northern Indiana Athletic Conference in 1976, although like Penn, they played in both leagues where schedules permitted. However, when Clay joined the Northern Indiana Athletic Conference in 1978, the schools broke off their relationship with the Catholic schools. Marian and St. Joseph continued on as independents for the next 27 years. With LaSalle closing in 2002, the Northern Indiana Athletic Conference discussed expanding beyond its seven schools, and took on both of the Catholic schools in 2005, so they absorbed every school in the Northern Indiana Valley Conference.
All schools located in St. Joseph County.
| School | Location | Mascot | Colors | Year joined | Previous conference | Year left | Conference joined | |
|---|---|---|---|---|---|---|---|---|
| Greene Township | Crumstown | Bulldogs | 1932 | 1965 | none (consolidated into Walkerton | |||
| Lakeville | Lakeville | Trojans | 1932 | 1965 | none (consolidated into LaVille | |||
| Madison Township | Wyatt | Panthers | 1932 | 1964 | none (consolidated into Penn) | |||
| New Carlisle | New Carlisle | Tigers | 1932 | 1966 | Northern State | |||
| North Liberty | North Liberty | Shamrocks | 1932 | 1966 | Northern State | |||
| South Bend Wilson | South Bend | Presidents | 1932 | 1950 | none (school closed) | |||
| Walkerton | Walkerton | Indians | 1932 | 1966 | none (consolidated into Glenn | |||
| South Bend Clay1 | South Bend | Colonials | 1939 1963 1974 | none (new school) Northern State Independents | 1958 1974 1978 | Northern State Independents Northern Indiana | ||
| Penn2 | Mishawaka | Kingsmen | 1958 | none (new school) | 1978 | Northern Indiana | ||
| South Bend Jackson | South Bend | Tigers | 1965 | none (new school) | 1975 | none (school closed) | ||
| South Bend LaSalle3 | South Bend | Lions | 1965 | none (new school) | 1978 | Northern Indiana | ||
| Mishawaka Marian | Mishawaka | Knights | 1967 | Independents | 1978 | Independents (Northern Indiana Athletic Conference 2005) | ||
| South Bend St. Joseph's | South Bend | Indians | 1967 | Independents | 1978 | Independents (Northern Indiana Athletic Conference 2005) |