- Sperco Associates, INC.
- Sperco Technology Group, LLC
- Spertus Institute For Jewish Learning And Leadership; Venue Six10
- Spinder Industries, LLC
- Spliff Society
- Sport Clips Haircuts
- Sports Illustrated Resorts
- Spothero
- Spr Consulting
- Sprocket Sports
- Sprout Social, INC.
- Spv Gold Valet
- Sqn Associates, LLC
- Squeeze INC.
- Srd Lobby Shop
- Srisai Printing LLC
- Srs Global Retail Solutions
- Srs Services Group
- Ss & C Technologies, INC.
- St Roger Abbey
- St. Regis Chicago
- St. Regis, Chicago Hotel
- Stacey-theory L.L.C.
- Stan's Donuts & Coffee
- Stan's Donuts And Coffee
- Stanard & Associates INC.
- Stancik Strategies LLC
- Stand-up Burgers
- Stantec Consulting Services INC
- Staples The Office Superstore #1611
- Star Brilliant
- Star Events
- Star Gems INC.
- Starasia INC
- Starbucks Coffee #16309
- Starbucks Coffee#2261
- Starbucks Palmer House
- Starcom Worldwide INC
- Starshak Winzenburg & Co.
- Start Early
- State Street Barbers
- State Street Souvenirs
- Stats LLC
- Stax INC.
- Staypineapple Chicago
- Steadfast Networks
- Steadfast Restaurant
- Stem Generation
- Sterling Bay Property Management, LLC
- Sterling Food Hall
- Steve & Kate's Camp, LLC
- Steve's Segway Tours, #1 Chicago Tours
- Steven Hopkins
- Stevie Fulton Shoe Parlor
- Stifel, Nicolaus & Company, Incorporated
- Stiom LLC
- Stocks & Blondes Bar & Grille
- Stop Everyday
- Straits Financial LLC
- Straits Row
- Strata Decision Technology, LLC
- Strata Decision Technology, LLC
- Strategex, LLC
- Strategic Employment Partners
- Strathmore Management INC
- Stratisphere Healthcare Solutions
- Stratus
- Stress Management Institute
- Strike Lending
- Strive Consulting
- Structure Re-right, INC.
- Stubhub
- Studio 8 Hair Salon
- Studio A
- Studio Lab, INC
- Studio Lynd, LLC
- Studio One Digital, INC.
- Subsciety
- Subway
- Subway
- Subway
- Subway
- Subway
- Subway
- Subway
- Subway / Jay Shree INC.
- Subway #26771
- Subway 44839
- Subway Sandwich
- Sue's Hallmark
- Sufi Dishes
- Sugar Bliss
- Sugar Bliss Patisserie
- Sugaring Nyc
- Sugarless Keto LLC
- Sugary Chicago
- Sulit LLC
- Summit Capital LLC
- Sun Trading LLC
- Sundac Inventory LLC
- Sunder Kesh Beautiful Co.
- Sunder Lux
- Sunshine Infinity, INC.
- Supercuts
- Supernova Networks
- Surfs Up South Loop LLC
- Suriya International INC
- Surplus Record LLC
- Sushi By Weight LLC
- Sushi Dokku
- Sushi Nova
- Sushi Plus Sushi Rotary Bar
- Sushi Sai
- Sushi-san
- Susquehanna Investment Group
- Sutter's Watch Repair
- Svoboda Capital Partners LLC
- Sw1's Exotic Reflections
- Swabian Treats
- Swap-o-rama
- Sweet Bean
- Sweet Futures 1, LLC
- Sweet Home Gelato
- Sweet Swabian
- Sweetgreen
- Sweets On The Block LLC
- Sweetwater
- Swift Impressions, INC.
- Swissotel Chicago
- Swl Marketing LLC
- Swoon Staffing
- Syd Jerome Men's Wear
- Sydel & Sydel LTD
- Sydney Taylor Skin
- Sylvia's Back Room
- Symmetri Marketing Group
- Synchronous Solutions INC
- Synectics INC.
- Synmeta
- T J Maxx # 724
- T-mobile
- T. N. Donnelly And Company / Chicago Loan Company
- T&co By Cherry Bekaert
- Ta Digital
- Taco Bell
- Taco Bell Cantina
- Taco Fresco
- Taco Maya
- Taco Rio
- Tahoe Partners LLC
- Taiber, Kosmala & Associates, LLC
- Tailor Barber Co.
- Taiwan Trade Center, Chicago
- Tak Korean Bistro & Karaoke
- Takher Forensic Consulting LLC
- Talent Intelligence INC
- Talentfoot Executive Search Frirm
- Talman Consultants, LLC
- Tamu: Restaurant And Sangria Bar
- Tandem
- Tandem Ventures, LLC
- Tango Parking INC
- Taqueria Decolores
- Tara Gehring
- Target (store T-2799)
- Taste Of Japan
- Taufe-hue Private Capital LLC
- Taureaux Tavern
- Tavern Club At 333
- Tavern Club Fitness
- Tawani Enterprises INC.
- Tawani Property Development LLC
- Tawani Property Management - Gold Coast
- Taxes Unlimited, INC.
- Taylor Made Software, INC.
- Taza
- Taza Mediterranean Cuisine
- Tbc South Loop
- Tcb Illinois Nfp, INC.
- Tcg Claims, LLC
- Tcs Education System
- Td Ameritrade, INC.
- Te'amo
- Tea Monster
- Teach Different
- Team Network
- Teamwerks
- Teamworking Cob LLC
- Teatro Zinzanni
- Tec Direct Media, INC.
- Techlaw
- Techlaw, INC.
- Technexus Holdings LLC
- Technical Assistance Corporation For Housing
- Technology Services Group, INC.
- Technology Support & Solutions, INC.
- Tecture, LLC
- Tegus, INC.
- Tejas Yoga
- Teksystems, INC.