Homer Thomas was educated in a small one room schoolhouse in Grant County, Indiana, before entering Marion High School. His time in Marion allowed him to excel both in the classroom and on the athletic field. He became a national high school record holder in the 12-pound hammer throw, an all-state halfback in football and an excellent bowler. His 12-pound hammer throw was well ahead of his competition. In 1902, his winning throw was 144-3, with an improvement in 1903 of 160-5 at the state finals at Indiana University. His dominance was reported to have come from his development of the three-turn delivery. Before Thomas' participation in the event, winning throws rarely surpassed 120 feet. It was reported that with an injured arm in 1902, he threw a winning record with only the use of one arm.