| Intuit Inc.Intuit - Small Business, Personal Finance and Tax Software | Financial Services | Mountain View | CA | > $1B |
| | Marketing and Advertising | Palo Alto | CA | $0 - 1M |
| IXL LearningIXL | Math, Language Arts, Science, and Social Studies Practice | E-Learning | San Mateo | CA | $10 - 50M |
| it's LearningLearning Management System (LMS) - E-Learning Software | itslearning | Information Technology and Services | Burlington | MA | $1 - 10M |
| InteliusFind People, Background Search, Criminal Check, Reverse Phone Lookup by Intelius | Internet | Bellevue | WA | $1 - 10M |
| | Publishing | San Francisco | CA | $10 - 50M |
| iContactitemprop="name">iContact - Email Marketing | Information Technology and Services | Morrisville | NC | $250 - 500M |
| IdealistVolunteer, work, intern, organize, hire and connect. Change the world - idealist.org | Nonprofit Organization Management | New York | NY | $1 - 10M |
| | International Trade and Development | Genve | GE | > $1B |
| InvaluableOnline Auctions & Galleries: Bid Live or Buy Now | Invaluable.com | Internet | Boston | MA | $1 - 10M |
| InfoCertInfoCert - Il futuro digitale è adesso | Information Technology and Services | Roma | Lazio | $1 - 10M |
| | Logistics and Supply Chain | Bristol | England | $1 - 10M |
| InformaticaInformatica: Data integration leader for Big Data & Cloud Analytics | Informatica US | Computer Software | Redwood City | CA | $500M - 1B |
| | Information Technology and Services | Elmwood Park | IL | $1 - 10M |
| ITworldIT news, careers, business technology, reviews | ITworld | Online Media | Framingham | MA | $1 - 10M |
| IDCIDC: The premier global market intelligence firm. | Market Research | Framingham | MA | $500M - 1B |
| IlluminaIllumina | Sequencing and array-based solutions for genetic research | Biotechnology | San Diego | CA | > $1B |
| | Computer Software | Midvale | UT | $100 - 250M |
| InstaMedHealthcare's Most Trusted Payments Network: InstaMed | Hospital & Health Care | Philadelphia | PA | $10 - 50M |
| | Biotechnology | Coralville | IA | $10 - 50M |
| | E-Learning | Richardson | TX | $0 - 1M |
| IntralinksSecure Virtual Data Rooms & Document Sharing by Intralinks | Computer Software | New York | NY | $100 - 250M |
| | Health, Wellness and Fitness | New York | NY | $100 - 250M |
| | Capital Markets | | | > $1B |
| InfluitiveInfluitive, the advocate marketing experts | Computer Software | Toronto | ON | $10 - 50M |
| | Financial Services | Washington | DC | $100 - 250M |
| | Computer Software | Indianapolis | IN | $100 - 250M |
| | Computer & Network Security | Lakeland | FL | $10 - 50M |
| | Computer Software | San Francisco | CA | $10 - 50M |
| InfoScoutReal-time Omnichannel Consumer & Shopper Insights | InfoScout | Market Research | San Francisco | CA | $1 - 10M |
| | Internet | El Segundo | CA | $100 - 250M |
| | Utilities | Liberty Lake | WA | > $1B |
| | Information Services | Agua Dulce | TX | $50 - 100M |
| | Computer Software | Foster City | CA | $10 - 50M |
| IxiaIxia Makes Applications Stronger | Computer Networking | Calabasas | CA | > $1B |
| | Information Technology and Services | Parsippany-Troy Hills | NJ | $50 - 100M |
| Instant Offices
Office Space for Rent USA | Executive Suites | Offices To Let | Office Rental | Real Estate | London | | $10 - 50M |
| | Internet | Hanover | NH | $1 - 10M |
| Iron MountainData Backup - Records Management - Shredding - Data Centers | Iron Mountain | Information Technology and Services | Boston | MA | > $1B |
| | Computer Software | Reno | NV | > $1B |
| | Financial Services | New York | NY | $250 - 500M |
| | Nonprofit Organization Management | Portsmouth | NH | |
| | Computer Software | Ronkonkoma | NY | $1 - 10M |
| | Higher Education | | | > $1B |
| | Internet | Framingham | MA | $100 - 250M |
| | Hospital & Health Care | Decatur | IL | $0 - 1M |
| | Marketing and Advertising | Reigate | England | |
| Iridium
Iridium Satellite Communications | Home
| Wireless | McLean | VA | $10 - 50M |
| | Pharmaceuticals | Burlington | MA | $500M - 1B |
| | Information Technology and Services | | | $1 - 10M |
| Insight DirectField Service Scheduling, Billing, Estimating, Dispatching Software | ServiceCEO | Computer Software | Boston | MA | $1 - 10M |
| | Online Media | Framingham | MA | $50 - 100M |
| iovation Inc.Multifactor Authentication and Online Fraud Prevention Solutions | iovation | Computer Software | Portland | OR | $10 - 50M |
| | Information Technology and Services | London | ON | $250 - 500M |
| | Information Technology and Services | | | $1 - 10M |
| ICS LearnICS Learn | Distance Learning Courses | Online Courses | Professional Training & Coaching | Glasgow | | $10 - 50M |
| | Publishing | Boston | MA | > $1B |
| iCaroliCarol | Crisis, Referral & Helpline Software for Non-Profits | Consumer Services | Oakville | ON | $1 - 10M |
| Iceland TravelIceland Travel - Iceland's leading Travel Company, Tour operator and DMC | Leisure, Travel & Tourism | Reykjav | | $10 - 50M |
| | Logistics and Supply Chain | Irvine | CA | |
| | Publishing | Bloomington | IN | $250 - 500M |
| ImprivataThe Healthcare IT Security Company | Imprivata | Computer Software | Lexington | MA | $50 - 100M |
| | Accounting | Singapore | | |
| | Online Media | Princeton | NJ | $0 - 1M |
| IOColocation Data Center as a Service | IO | Information Technology and Services | | | $50 - 100M |
| | Health, Wellness and Fitness | Logan | UT | $500M - 1B |
| | Think Tanks | McLean | VA | $1 - 10M |
| | Security and Investigations | Beachwood | OH | $10 - 50M |
| | Aviation & Aerospace | Los Angeles | CA | $10 - 50M |
| | Computer Software | Kirkland | WA | $1 - 10M |
| | Education Management | Mumbai | Maharashtra | $1 - 10M |
| | Information Technology and Services | Rockville | MD | $0 - 1M |
| | Religious Institutions | BARRE | MA | $0 - 1M |
| iBwave Solutions Inc.iBwave in-building wireless network design planning and deployment solutions: iBwave | Wireless | Montreal | QC | $10 - 50M |
| | Online Media | San Francisco | CA | |
| | Higher Education | Wilmington | DE | $1 - 10M |
| | Information Technology and Services | Santa Ana | CA | $50 - 100M |
| InfoArmorEmployee Identity Protection Services, Advanced Threat Intelligence | InfoArmor | Information Technology and Services | | | $0 - 1M |
| | E-Learning | MARIETTA | GA | $0 - 1M |
| InesdiDigital Business School INESDI | Formaci??n especializada en la nueva econom??a digital | Professional Training & Coaching | Barcelona | Catalonia | $1 - 10M |
| | Computer Hardware | Seattle | WA | $0 - 1M |
| | Nonprofit Organization Management | Buenos Aires | | $10 - 50M |
| | E-Learning | Manchester | NH | $0 - 1M |
| | Legal Services | New York | NY | $0 - 1M |
| InformzEmail Marketing Solutions for Associations & Nonprofits | Information Technology and Services | saratoga springs | NY | $10 - 50M |
| IronRidge
Solar Mounting and Racking - IronRidge
| Renewables & Environment | Willits | CA | $0 - 1M |
| | Investment Management | Irvine | CA | $1 - 10M |
| | Electrical/Electronic Manufacturing | Oakdale | PA | $250 - 500M |
| InfoScoutReal-time Omnichannel Consumer & Shopper Insights | InfoScout | Market Research | San Francisco | CA | $1 - 10M |
| InvocaInvoca | Call Tracking & Analytics - 1-888-989-4996 | Marketing and Advertising | Santa Barbara | CA | $10 - 50M |
| | Logistics and Supply Chain | Glendale Heights, IL | | $0 - 1M |
| | Financial Services | Tel Aviv | | $50 - 100M |
| | Nonprofit Organization Management | New York | NY | $0 - 1M |
| Ivy CollegeIvy College - Accredited Online Courses for Australians | E-Learning | | | |
| imavexIndianapolis Web Design, Internet Marketing, & SEO - imavex | Internet | Noblesville | IN | $1 - 10M |
| ImageX MediaDrupal Web Design & Development in Vancouver BC | ImageX | Internet | Burnaby | BC | $1 - 10M |
| | Professional Training & Coaching | Sutton Coldfield | | $10 - 50M |
| IntappIntapp - Software for a Changing Legal Market | Computer Software | Palo Alto | CA | $1 - 10M |
| | Environmental Services | Seattle | WA | $0 - 1M |
| | Retail | SALT LAKE CITY | UT | $0 - 1M |