William Booth Gill

William Booth Gill (1928–2007) was an Australian Anglican missionary stationed at Boianai, Papua New Guinea. On 26 and 27 June 1959, together with 37 other witnesses — including teachers and medical staff — he observed for more than four hours a large disc-shaped craft with humanoid figures on its upper surface; four figures waved back when Gill waved. The Boianai encounter, because of its many credible witnesses, its extremely long duration and its apparent interaction, counts among the strongest close-encounter cases of all.

• Australian Anglican missionary (1928–2007)
• Stationed at Boianai, Papua New Guinea
• Sighting on 26/27 June 1959 with humanoid figures on the upper surface of the object
• Observation lasted over four hours across two nights
• Gill and 37 other witnesses, including teachers and medical staff
• Four figures waved back when Gill waved
• Investigation by the Royal Australian Air Force; significant through multiple witnesses, duration and interaction

For the UAP timeline, Gill is one of the strongest multi-witness close-encounter cases of the southern hemisphere: an Anglican missionary together with medical and teaching staff makes the Boianai sighting a standard entry against which any serious discussion about "interaction with UAP occupants" must be measured.