The annual event is this year celebrating its nonacentennial.
The 2025 festivities got under way on Saturday (May 3), with Boston Borough Council mace bearer Andy Lamming performing the traditional proclamation.
The fair will remain in town until Sunday.
It opened today at 11am and will close at 10pm.
It will be open from 3-10pm tomorrow, Wednesday, Thursday and Friday, from 11am to 10.30pm on Saturday, and from 11am to 8pm on Sunday.
On that Sunday, from 11am to 1pm, a quiet and sensory session will be held. During these times, the fair music and lights will be turned off.

9. Opening of Boston May Fair 2025
Benas Ragelis, four, of Boston. Photo: D. R. Dawson Photography

10. Opening of Boston May Fair
Medieval-themed street performers providing entertainment during Saturday's opening of Boston May Fair. Photo: D. R. Dawson Photography

11. Opening of Boston May Fair 2025
A closer look at the knight and his noble steed. Photo: D. R Dawson Photography

12. Opening of Boston May Fair 2025
Boston May Fair has returned to the town centre. Photo: D. R. Dawson Photography