The Unknown Warrior died in France sometime between April 1916 and November 1918.
He was originally buried in Caterpillar Valley Cemetery near Longueval, the site where the New Zealand Division first fought the Battle of the Somme, before his exhumation and interment at the National War Memorial in 2004.
People will be able to lay flowers and wreaths at his tomb.
Arts, Culture and Heritage minister Maggie Barry said the commemoration was a chance to pay tribute to those who served in France.
The centenary of the Battle of the Somme in France is on 15 September. Minister Gerry Brownlee will represent New Zealand at three services at Longueval in northern France.
● Information for people wanting to attend the War in France national commemoration can be found at ww100.govt.nz/war-in-france.
● For more information about the international commemoration marking the centenary of the Battle of the Somme, visit ww100.govt.nz/battle-of-the-somme-centenary.