| Ring's End, Incorporated | Retail Trade | $8,058,147 | $6,542,270 | 467 | $96.4M |  Research |
| Felix F., Callari Inc. | Wholesale Trade | $1,941,500 | $1,959,372 | 139 | $42.6M | Research |
| E C Scott Group Llc. | Wholesale Trade | $1,515,768 | $1,523,949 | 53 | $13.6M | Research |
| Applied Psychological Techniques Inc. | Professional, Scientific, and Technical Services | $1,301,503 | $1,318,868 | 70 | $7.2M | Research |
| Darien Community Young Men's Christian Association | Other Services (except Public Administration) | $1,038,776 | $1,157,827 | 422 | $80.6M | Research |
| Ec Scott Group LLC | Wholesale Trade | $1,036,200 | $1,046,221 | 63 | $16.2M | Research |
| Darien Community Young Men's Christian Association Inc. | Other Services (except Public Administration) | $1,006,403 | $1,011,503 | 278 | $53.1M | Research |
| Breeze Aviation Group, Inc. | Transportation and Warehousing | $969,382 | $976,217 | 59 | $15.0M | Research |
| Roosevelt & Cross Incorporated | Finance and Insurance | $920,525 | $941,007 | 43 | $22.1M | Research |
| A Royal Flush | Administrative and Support and Waste Management | $860,000 | $864,618 | 71 | $13.4M | Research |
| Sasco River Center ,llc | Health Care and Social Assistance | $744,800 | $670,415 | 56 | $9.1M | Research |
| E L Wagner Company Incorporated | Construction | $629,171 | $634,360 | 49 | $55.8M | Research |
| Darien Sport Shop | Retail Trade | $628,800 | $634,948 | 48 | $14.5M | Research |
| Bardlee Enterprises, LLC | Finance and Insurance | $610,100 | $0 | 36 | $18.5M | Research |
| Darien Sport Shop Inc. | Professional, Scientific, and Technical Services | $556,900 | $562,655 | 61 | $8.5M | Research |
| Ufs Industries, Inc. DBA Sally Sherman Foods | Wholesale Trade | $538,525 | $544,213 | 73 | $18.8M | Research |
| Sun Hollow Restaurant Corporation | Accommodation and Food Services | $528,171 | $534,040 | 39 | $6.9M | Research |
| Dom's Landscaping, Inc. | Professional, Scientific, and Technical Services | $491,923 | $494,958 | 35 | $7.1M | Research |
| Daigle & Travers Insurance Agency LLC | Finance and Insurance | $490,800 | $493,409 | 31 | $15.9M | Research |
| Quality Taco LLC | Accommodation and Food Services | $490,395 | $493,256 | 30 | $5.3M | Research |
| Touchpoint Integrated Communications LLC | Professional, Scientific, and Technical Services | $460,462 | $463,251 | 21 | <$5M | Research |
| Noroton Presbyterian Church | Other Services (except Public Administration) | $458,700 | $462,055 | 48 | N/A | Research |
| Karen Kluger | Professional, Scientific, and Technical Services | $447,788 | $449,430 | 21 | <$5M | Research |
| H&l Chevrolet | Retail Trade | $430,015 | $433,125 | 25 | $6.3M | Research |
| Lanphier Day Spa, LLC | Other Services (except Public Administration) | $418,330 | $423,067 | 45 | $8.6M | Research |