| Cycle Num: | 3 |
| Start Date: | June 1775 |
| End Date: | September 1784 |
| Duration: | 9.3 |
| Max Count: | 264.3 |
| Max Count Date: | May 1778 |
| Min Count: | 12.0 |
| Prev Name: | Solar cycle 2 |
| Prev Dates: | 1766–1775 |
| Next Name: | Solar cycle 4 |
| Next Dates: | 1784–1798 |
Solar cycle 3 was the third solar cycle since 1755, when extensive recording of solar sunspot activity began.[1] The solar cycle lasted 9.3 years, beginning in June 1775 and ending in September 1784. The maximum smoothed sunspot number observed during the solar cycle was 264.3 (May 1778), and the starting minimum was 12.0.[2]
William Herschel began observing sunspots during this period.[3]