The Tommy Westphall universe hypothesis makes the claim that not only does St. Elsewhere take place within Tommy’s mind, but so do numerous other television series which are directly and indirectly connected to St. Elsewhere through fictional crossovers and spin-offs, resulting in a large fictional universe taking place entirely within Tommy’s mind.

St. Elsewhere writer Tom Fontana was quoted as saying, “Someone did the math once… and something like 90 percent of all [American] television took place in Tommy Westphall’s mind. God love him.”