Instant runoff voting used for major organizational elections based on Robert's Rules of Order
Robert's Rules of Order (RRO) has been the basis for dozens of major private associations and more than fifty colleges and universities choosing to elect officers with instant runoff voting . RRO clearly spells out the rules for an instant runoff elections, to the point that association bylaws often simply say "officers shall be elected by preferential voting as detailed in Robert's Rules of Order."
RRO recommends IRV (which it calls "preferential voting," a term also used to describe IRV in Australia) when association members aren't all in the same place and able to engage in repeated balloting. All the organizational bylaws FairVote has examined with IRV rules follow the model we recommend them for public elections, with one round of voting, and the winner being the candidate who has a majority of votes in the final round of counting. IRV is used for high-profile awards, from the Oscars (which first did so to choose best picture back in the 1930s and 1940s and will start again this winter) to the Hugo Awards for science fiction.
Associations electing top officers with IRV (some of which have very hotly contested elections) include: the American Association of University Women (approximately 100,000 members), American Chemical Society (the world's largest scientific society), American Medical Student Association (oldest and largest independent association of physicians-in-training in the United States), American Mensa (more than 50,000 members), American Political Science Association (the leading professional organization for the study of political science, with more than 15,000 members in over 80 countries); American Psychiatric Association (more than 38,000 members worldwide); American Psychological Association (approximately 150,000 members).
And that's just the letter "A'.
Here are links to a more complete list of associations and list of colleges and universites using IRV to elect leaders.