When Sir John William Dawson became McGill’s principal in 1855, cows still roamed parts of the campus. Over the next four decades, he would transform McGill from a small but ambitious college into a full-fledged (and widely respected) institution of higher learning. In fact, at the time of Dawson’s death in 1899, the Times of London wrote “…the progress of that institution under his guidance was marvellous. McGill has grown into a richly, though not too richly, endowed University with about 1,300 students and a prestige only excelled in America by that of Harvard.” With all he did for McGill, his own accomplishments are often overlooked. Born in Pictou, Nova Scotia, he was a highly influential geologist and the first Canadian-born scientist to achieve worldwide recognition. Working with Sir Charles Lyell, Dawson discovered some of the earliest known reptile specimens. He also produced 25 books, more than 150 scholarly articles, and several works of popular science during his career – all while serving as McGill’s chief administrator! A founding member and first president of the Royal Society of Canada, he is also the only person to serve as president of both the American and the British Associations for the Advancement of Science. At the end of the day, Dawson is the Greatest McGillian because, without his leadership as an academic and administrator during the University’s formational period, McGill may have never gotten off the ground.