There are 15 words that start with 'cotto'.
| cotton | cottons | cottony |
| cottoned | cottoning | cottonseed |
| cottontail | cottonweed | cottonwood |
| cottonmouth | cottonseeds | cottontails |
| cottonweeds | cottonwoods | cottonmouths |
Note: These 15 words that start with 'cotto' are found from the USA & Canada version of the tournament Scrabble word list.