A "Ula" throwing club - similar to the type of weapon used to kill him - and a Maori canoe bailer are to go under the hammer.
Williams and his wife Mary travelled on their first missionary expedition to the South Pacific in 1817.
They visited Tahiti and other island chains including the Cook Islands to spread the Gospel and were the first missionary family to visit Samoa.
They returned to Britain in 1834 where John supervised the printing of his translation of the New Testament into the Rarotongan language of the Cook Islands.
He also published his Narrative of Missionary Enterprises in the South Sea Islands before returning to the region.
In 1839, while visiting Erromango, Vanuatu, he and fellow missionary James Harris were killed and eaten by cannibals.
The natives of those islands recently received The Prince of Wales and made him an honorary high chief.
In 2009 the descendants of Williams went to the islands where locals apologised on behalf of their ancestors who ate the missionaries.
The items are being sold at Duke's auction house in Dorchester, Dorset, on Thursday.
The throwing stick is estimated to fetch between £500 and £1,000 while the canoe bailer could sell for between £800 and £1,500.
John Holmes from the saleroom said: "These items are very evocative and have this great provenance.
"To have them consigned by the descendants of Williams himself is of great importance and means they might sell for much more than they estimate.
"Williams and his wife and their two children who grew into adulthood were hugely successful missionaries.
"They worked for the London Missionary Society and John learned the local languages and customs of the people in the South Pacific and was widely respected.
"These two items we believe were brought back with him when he returned to Britain in 1834 and have remained with the family.
"During that return he also brought home a Samoan man called Leota who lived out his days as a Christian in London.
"After returning to the South Pacific, Williams decided to go to what was known as the New Hebrides where locals had the reputation of being some of the fiercest cannibals in the region, but he trusted in his faith.
"The natives, however, who had previously been mistreated by the crew of a trading ship, chased Williams and James Harris before beating them to death and eating them.
"Shortly after Williams' death a memorial stone was erected on the Cook island of Rarotonga and it is still there.
"Objects from these islands are often difficult to date and authenticate, but with these we know where they've been since they were brought back by Williams.
"There are a number of other items of ethnographica in an interesting sale."
Stay up to date with the latest news stories from a Christian perspective. Sign up to our daily newsletter and receive more stories like this straight to your inbox every morning.
