- Calder Bros. Co.1
- Carthage Creamery Co.1
- Cedar Rapids Cooperative Dairy Co.1
- Charles F. Umland, t/a Pulaski Country Cheese Co.1
- Charles F. Umland, trading as the Colfax Cheese Co.1
- Charles Mullen1
- Cheese Products Co., Inc.1
- Chicago, Milwaukee, St. Paul & Pacific Railroad Co.1
- Cissna Park Cheese Co.1
- Clarence D. Davis, Inc.1
- Clover Leaf Cheese Factory1
- Clyde K. Green and Edgar M. Urevig, copartners, trading as Granada Cheese Factory1
- Coldwater Dairy Products Co.1
- Community Creamery Co.2
- Concordia Creamery Co.1
- Consolidated Dairies1
- Consolidated Dairies of Lake County, Inc.1
- Consumer-Farmer Milk Cooperative, Inc.1
- Cuba Cheese & Trading Co., Inc.1
- Cudahy Packing Co.1