The clean-up will be held on Saturday, July 7, from 2pm to 4pm - with a meeting point at Stanhope Hall, on Boston Road.
Volunteers will be mainly litter-picking and weed pulling around the town and on some of the main routes into the town.
A spokesman for Horncastle Town Council said: “All the volunteers who helped out at the last clean up did a fabulous job.
“We’d love to see you again at this clean up and would welcome some new faces too.
“Let’s get our town looking great.”
All equipment will be provided and refreshments will be available.
For more information, call Michelle or Amanda at Horncastle Town Council on 01507 522597.