| QuickPractice | New York |
| Quickskills, LLC | Delaware |
| QuickSoftPro | Pennsylvania |
| Quickstaff | New York |
| QuickStart | California |
| QuickTel | Washington |
| Quickwit, Inc. | California |
| Quicomm | Florida |
| Quid | California |
| QuidelOrtho Corporation | California |
| Quidient, LLC | |
| Quiet PC USA | California |
| Quigley BioPharma, LLC | |
| Quigley-Simpson | |
| QUIK | |
| Quik Website Design & Consulting, Inc. | Virginia |
| Quikly, Inc. | |
| QuikStor Security and Software | California |
| QuikTek Info Services | |
| Quikzer Technology, LLC | |
| QuilBot (Course Hero), LLC | Illinois |
| Quill & Mouse Studios, Inc. | Florida |
| Quillin | |
| Quilt Health | |
| Quilter | |
| QuiltSOFT | California |
| Quiltt, Inc. | |
| Quince Therapeutics | |
| Quincy Center for Innovation | |
| Quincy University | Illinois |
| Quindar | |
| Quinn Interactive, Inc. | California |
| Quinn-Curtis | Massachusetts |
| Quinnconcepts | |
| Quinnipiac University | Connecticut |
| Quinnox, Inc. | Illinois |
| Quinstar Technology, Inc. | California |
| Quintara Biosciences | California |
| Quintara Discovery, Inc. | California |
| Quinte Financial Technologies | New York |
| Quintech | Pennsylvania |
| Quintessent | |
| Quintessential School Systems | Illinois |
| Quintillion | Alaska |
| Quintron Systems, Inc. | California |
| Quiq | Montana |
| Quiqhiq.com | California |
| Quirky | |
| QuirkyCube Software | |
| Quisitive | Texas |