Freeman Dyson is a more recent example. He became professor of physics at Cornell in 1951 despite never having earned a PhD. He had earned a BA at Cambridge just after WW2, and I believe he obtained a Master's degree at some point too.

Freeman Dyson went on to contribute to a multitude of areas, with numerous papers on mathematics before he reached the age of 20. He worked on many high concept space-related ideas, such as Project Orion and the Dyson sphere. While he was never involved in the Manhattan Project, he worked with many who did, and was later involved in writing papers on strategy and use of nuclear weapons. He died 18 months ago.

Freeman Dyson could be considered a more recent example. He became professor of physics at Cornell in 1951 despite never having earned a PhD. He had earned a BA at Cambridge just after WW2, and I believe he obtained a Master's degree at some point too. While these two degrees definitely count as 'formal education', it is generally thought that it's the PhD that does the most towards preparing someone for academic life. In this regard, the granting of a professorship without a PhD is highly unusual.

Freeman Dyson went on to contribute to a multitude of areas, with numerous papers on mathematics before he reached the age of 20. He worked on many high concept space-related ideas, such as Project Orion and the Dyson sphere. While he was never involved in the Manhattan Project, he worked with many who did, and was later involved in writing papers on strategy and use of nuclear weapons. He died 18 months ago.