Leonid Stepanovych Stadnyk (Ukrainian: Леонід Степанович Стадник; 5 August 1970 – 24 August 2014) was a Ukrainian man who allegedly stood at 8 feet 5 inches or 2.57 meters tall.
Stadnyk's excessive growth began after brain surgery at the age of 14, after which he developed a pituitary gland tumor that caused the gland to secrete large amounts of growth hormone. This resulted in what doctors describe as acromegalic gigantism. Twenty years after the surgery, the doctors discovered the tumour had mysteriously disappeared and he was currently healthy. He reportedly wore US size 24.5 shoes. On 8 September 2007, Guinness book's spokeswoman Amarilis Espinoza stated that in the 2008 edition of the record book, Mr. Stadnyk appeared to be taller than Bao Xishun, a native of Inner Mongolia in China who stands 7 ft 8.95 in (2.3609 m). Although he held the title for a month, Stadnyk having no interest in being in any record book, refused to be measured, ending his GWR recognition. Others have questioned the legitimacy of his record, noting that Stadnyk had never been officially measured by Guinness World Records, only by the "Ukrainian Book of Records" that says that he measures 2.57 m (8 ft 5.2 in).