| Route | From | To | Dates | Now |
| 341 | "Airport" | "Nearest Town" | 1937 | Various |
| Connects any airport without a state highway nearby to the nearest town | ||||
| 342 | Springside | SR 14 near Francis | 1937 | |
| 343 | Fruitland | Georgetown Point | 1937 | |
| 344 | Samsula | SR 12 | 1937 | |
| 345 | SR 14 near Federal Point | Hastings | 1937 | |
| 346 | SR 5 S of Floral City | E of Chesahowitska Springs | 1937 | |
| 347 | SR 90 near Blue Springs | Hornsville | 1937 | |
| 348 | SR 13 S of Bryceville | Otis | 1937 | |
| 349 | Lake Placid | Brighton | 1937 | |
| 350 | Caryville | New Hope | 1937 | |
| Designated "Cone Highway" | ||||
| 351 | SR 45 near Electra | SR 2 near Moss Bluff | 1937 | |
| 352 | Havana | Iamonia | 1937 | |
| 353 | South Bay | SR 194 near Pahokee | 1937 | |
| 354 | Woodville | SR 130 E of Natural Bridge | 1937 | |
| 355 | Ortona | Goodno | 1937 | |
| 356 | Bradenton | Sarasota | 1937 | |
| 357 | SR 2 N of Olga | 1937 | ||
| 358 | SR 40 near Liberty School House | Holmes Co. line near Alabama state line | 1937 | |
| 359 | Auburndale | Waverly | 1937-1945 | SR 655, CR 544A, SR 544, US 17, SR 540, CR 540, SR 540, CR 540 |
| 360 | Maderia Beach | Clearwater | 1937 | |