Accomplished autodidact theoretical computer scientists While it is very common to see successful autodidact musicians, painters, authors and architects - I am not familiar with any famous autodidacts in the field of TCS.
Are there any examples of an accomplished autodidact theoretical computer scientist (i.e., someone who published a significant paper, without ever going to grad school) ?
In addition to some of the great people listed in the comments, Gregory Chaitin independently developed much of Kolmogorov complexity while he was a highschool student in New York city.