Gary Keller is a renowned real estate expert, co-founder, and chairman of Keller Williams Realty International, which expanded from a single office in Austin, Texas, to become one of the largest real estate companies in the world. His professional focus is on teaching and coaching, helping others make informed real estate decisions.

In addition to his business achievements, Keller is an accomplished author, known for the best-selling Millionaire Real Estate book series, which includes titles such as The Millionaire Real Estate Agent and The Millionaire Real Estate Investor. He emphasizes leadership as "teaching people how to think the way they need to think so they can do what they need to do when they need to do it, so they can get what they want when they want it."

Keller's impact extends beyond real estate; his books aim to inspire and provide practical tools for success. His personal life features a strong family foundation with his wife, Mary, and their son, John.