| 5233 | Kitchenware stores, retail | |
| 5139 | Kitchenware, ceramic, wholesale | |
| 2691 | Kitchenware, china, earthenware, pottery or stoneware, manufacturing | |
| 2691 | Kitchenware, commercial and household type, vitreous china, manufacturing | |
| 2691 | Kitchenware, semivitreous earthenware, manufacturing | |
| 5239 | Kite (toy) stores, retail | |
| 3694 | Kites, manufacturing | |
| 3699 | Kits, hosiery, sewing and mending, manufacturing | |
| 9199 | Kiwanis club | |
| 0113 | Kiwi fruit farming | |
| 3210 | Klystron tubes, manufacturing | |
| 1721 | Knapsacks (e.g., backpacks, book bags), manufacturing | |
| 3311 | Kneecap supporters, orthopedic, manufacturing | |
| 1810 | Knickers, men's and boys', cut and sewn from purchased fabric | |
| 1810 | Knickers, women's and misses', cut and sewn from purchased fabric | |
| 5260 | Knife and scissors sharpening | |
| 2893 | Knife blades, manufacturing | |
| 2893 | Knife blanks, manufacturing | |
| 2930 | Knife sharpeners, electric, manufacturing | |
| 5260 | Knife sharpening and repair shops | |
| 3120 | Knife switches, electric, manufacturing | |
| 9199 | Knights of Columbus | |
| 1541 | Knishes (except frozen), made in commercial bakeries | |
| 1730 | Knit fabrics, dyeing or finishing | |
| 5131 | Knit fabrics, wholesale | |
| 1810 | Knit gloves, made from purchased fabric | |
| 1730 | Knit gloves, made in knitting mills | |
| 5232 | Knit wear, ladies', retail | |
| 5131 | Knit wear, wholesale | |
| 5131 | Knitted cloth, piece goods, wholesale | |
| 1711 | Knitting and crochet thread, manufacturing | |
| 1730 | Knitting and finishing fabric | |
| 1730 | Knitting and finishing hosiery and socks | |
| 1730 | Knitting and finishing warp fabrics | |
| 1730 | Knitting and finishing weft fabric | |
| 1730 | Knitting fabric | |
| 1730 | Knitting hosiery and socks | |
| 1730 | Knitting hosiery, on a contract basis | |
| 2926 | Knitting machinery, manufacturing | |
| 1730 | Knitting men's and boys' clothing (except hosiery), on a contract basis | |