C
- Cadillac Fairview Urban Development, Inc.
- Cameron Iron Works, Inc. & Ltd
- Celanse Corporation
- Centex Corporation
- Citibank
- Citizens Communication
- Citizens Utilities
- City of Austin, Texas
- City of Dallas, Texas
- City of Frisco,Texas
- City of Garland,Texas
- City of Houston, Texas
- City of Richardson,Texas
- Clark Bardes, Inc.
- Coca-Cola
- Compaq Computer
- Community Credit Union
- Continental Airlines
- Coopers & Lybrand
- Cushman & Wakefield
D
- Dallas Country Club
- Dallas County Community College District / El Centro College
- Dallas Independent School District
- Delta Air Lines
- Dresser Industries, Inc.