James Douglas Muir Leno is an American comedian best known as the host of the popular NBC television program The Tonight Show. He grew up in Andover, Massachusetts, and received his Bachelor's degree in Speech therapy from Emerson College in 1973. He suffers from a slight form of dyslexia.

Known for his work ethic and his "nice" demeanor, Leno started his career as a stand-up comic performing in nightclubs, bars and any place that would give him even five minutes of stage time. Though he had made the occasional foray onto television in the form of guest appearances on The Tonight Show, then hosted by Johnny Carson, stardom eluded him and he continued to work wherever he was allowed. It has been reported that Leno would sometimes work as many as eight or nine clubs in one evening. He began making more frequent appearances on television when many of his friends and contemporaries became more influential on late night programs. Leno made a record number of appearances on Late Night with David Letterman. His popularity was noted by NBC executives, who decided to make Leno the permanent guest host for The Tonight Show when Joan Rivers left that position.

When Carson retired in 1992 Jay Leno became the new permanent host of The Tonight Show after a long period of debate and negotiation between the network, Leno, and David Letterman (who had been considered by many to be Carson's heir apparent); Letterman soon signed a deal with CBS, sparking an ongoing late-night rivalry between the two talk-show hosts. Although Letterman's Late Show led in the ratings from the start, The Tonight Show took over the lead in 1995 and has, on the whole, had higher ratings ever since.