Thousands of people are expected to line the streets as the 35-year-old, pictured above in London, parades through the town centre in an open-top bus.
Ben, the most decorated sailor in Olympic history, has lived in the town since the late 1990s.
He said: “The support I have received from the people of Lymington over the years has been nothing short of amazing.
“The open-top bus tour will be a great way to show my appreciation and will also give me a chance to say hello to many friendly faces.”
Ben triumphed in the Finn class at Weymouth last month, winning his fourth consecutive gold medal. He also took silver at the Atlanta Games in 1996.
Lymington’s mayor, Councillor Jacqui England, said: “We’re all so proud of him and really pleased he’s managed to arrange this visit.”
The double-decker bus will move off from the Lymington New Forest Hospital in Wellworthy Road just after 5pm.