- Chicago Homes One
- Chicago Human Rhythm Project
- Chicago Ink And Toner Irepair
- Chicago Invisible Setters., INC
- Chicago Jobs Council
- Chicago Kernel Gourmet Popcorn
- Chicago Lakefront Cruises LLC
- Chicago Latino Theater Alliance
- Chicago Loop Alliance
- Chicago Lunchbox
- Chicago Metro Mart INC.
- Chicago Metropolitan Housing Development Corporation
- Chicago Minority Supplier Development Council
- Chicago Multi-cultural Dance Center
- Chicago Opera Theater
- Chicago Parking Meters, LLC
- Chicago Passport & Visa Expedite Services, LLC
- Chicago Pawnbroker INC.
- Chicago Poster Restoration INC
- Chicago Property Tax Appeal And Recovery
- Chicago Public Library Foundation
- Chicago Recording Company
- Chicago Recording Company
- Chicago Retroboats
- Chicago Setting Jewelers Corp.
- Chicago Sinfonietta INC.
- Chicago Sister Cities International
- Chicago Sports Novelty
- Chicago Symphony Orchestra/the Orchestral Association
- Chicago Tai Chi
- Chicago Tax Consultancy LLC
- Chicago Tech Support, Tech Support Me
- Chicago Theater
- Chicago Theatre Group, INC.
- Chicago Trading Company
- Chicago Trolley Co.
- Chicago Twenty Something
- Chicago United Industries,ltd.
- Chicago Upscale Clean Team
- Chicago Valet
- Chicago Venture Partners
- Chicago Water Taxi
- Chicago Watercraft
- Chicago Yacht Club
- Chicago Youth Centers
- Chicago Youth Symphony Orchestras
- Chicagoland Community Management, INC.
- Chick-fil-a
- Chick-fil-a At Millennium Park (il) In-line
- Chick-fil-a Millennium Park
- Chick-fil-a State And Lake In-line
- Chicken Planet
- Chifam, LLC.
- Children's Home & Aid
- Children's Research Triangle
- Chipotle Mexican Grill
- Chitown Food & Deli
- Chiya Chai Cafe
- Chkn - Box
- Chowbus
- Chris Martin
- Chris Watch Repair, INC.
- Christian Century
- Christopher Romani
- Christopher Vukasin
- Christopher's Attic Vintage
- Chun Lam
- Cibc Private Wealth Advisors
- Cibc Theatre
- Cielo Concessions, LLC
- Cimco, A Division Of Comcast Business Services
- Circana, INC
- Circle K
- Circle K
- Citadel Enterprise Americas LLC
- Citadel Property Advisors
- Citigroup Global Markets, INC.
- Citizenm Chicago Downtown Hotel
- Citrine Informatics, INC.
- City Bee Savers
- City Loft LLC
- City Rock
- City Social
- City Staffing Services INC
- City Winery Chicago
- Civc Partners, L.P.
- Civcon Services, INC.
- Civic Consulting Alliance
- Civis Analytics, INC.
- Cjg Consulting, LLC
- Cjl Resources LLC
- Ckearedge Solutions INC.
- Clareo
- Clarity Partners
- Clarius Partners, LLC
- Clark Street Cleaners
- Claro Healthcare, LLC
- Classical Music Chicago
- Clean Windows R Us
- Clear Channel Airports
- Clear Channel Outdoor
- Clemons & Company Holdings, LLC
- Cleo's Southern Cuisine
- Cleveland-cliffs Steel LLC
- Clinical Outcomes Solutions
- Clothe Me Thriftique
- Club Craftsmen
- Club Pilates South Loop
- Club Quarters
- Club Quarters Central Loop
- Cmm Food Services INC
- Cmms Data Group, INC.
- Cn Discounts, INC.
- Cobra Lounge
- Cochan Volant
- Cocobar
- Code Of Conduct
- Code Platoon
- Codifyd INC.
- Coeur Mining, INC.
- Cogent Communications, INC.
- Cogent Strategic Wealth
- Cognitive Capital, LLC
- Cohen Financial Management Of Raymond James
- Coherent Economics, LLC
- Cohesiveft
- Collier Jewelry & Watch Sales
- Colliers
- Color In The Loop Salon LLC
- Colson Associates, INC.
- Columbia Capital Management, LLC
- Columbia College Chicago
- Columbia Wanger Asset Management LLC
- Columbia Yacht Club
- Columbus Building Cafe
- Commongrounds Workplace
- Community Desk Chicago
- Community Tax, LLC
- Comperemedia
- Competive Piping Systems INC
- Comprehensive Construction Consulting, INC.
- Compucity INC
- Computer Aid INC
- Computerized Facility Integration, LLC
- Comscore, INC.
- Comtek International, INC.
- Comvest Capital Advisors, LLC
- Concern Worldwide Us INC
- Concierge Unlimited Inernational
- Concord Sheridan LP
- Concorde
- Concrete Communication LLC
- Concrete Strategies LLC
- Conduent Business Services, LLC
- Conexiom
- Conference Center Concepts LLC
- Congaree River LLC
- Congress Plaza
- Conn-selmer, INC.
- Connamara Systems, LLC
- Connecthr LLC
- Connection Matters, INC.
- Conotoxia, INC.
- Consolidated Trading LLC
- Constellation New Energy INC.
- Consultigence Corporation
- Contigo Brands, Bubba Brands,rubermaid Beverage,ignite USA
- Continental Advisors LLC
- Continental Materials Corp
- Continuum
- Control Risks Group, LLC
- Convene
- Convene
- Convene At 16 West Adams / Convene At 131 South Dearborn
- Convene At 311 West Monroe/for Five Chicago
- Convenience 35
- Converge Medical Technology LLC
- Cooley LLP
- Cooper Coleman
- Cooperativa Ceramica D'imola North America INC
- Copper Club
- Coralie Coffee
- Corcoran Expositions, INC
- Core Erectors Il LLC
- Corepower Yoga
- Corner Bakery Cafe
- Corner Bakery Cafe 167
- Cornerstone Research, INC.
- Corporate Concepts, INC.
- Corporate Concierge Services, INC.
- Corporate Traveler, Fcm Travel Solutions
- Cosentini Associates, INC.
- Cotter Consulting INC.
- Cox & Kings Global Services USA LLC
- Cox Commercial Cleaning
- Cps Parking
- Cqg
- Crafty Cafe
- Crafty Cafe
- Crafty Cafe - 20 S Wacker, LLC