Uncle Henry is a fictional character from The Oz Books by L. Frank Baum. He is the uncle of Dorothy Gale and husband of Aunt Em, and lived with them on a farm in Kansas.
After their house was famously carried off to the land of Oz by a tornado in The Wonderful Wizard of Oz, Henry mortgaged his farm in order to rebuild. This crisis, combined with the stress of Dorothy's prolonged disappearance and sudden reappearance, took a toll on his health, and his doctor ordered him to take a vacation. He took Dorothy with him on an ocean voyage to Australia, where he had relatives, but during this trip (in Ozma of Oz) Dorothy was lost again during a storm, and for several weeks a despondent Henry believed she had drowned, until she suddenly returned again, courtesy of the Nome King's Magic Belt.
In The Emerald City of Oz, Henry and Em finally confessed to Dorothy the extent of their financial problems, and revealed to her that their farm was on the verge of foreclosure. Dorothy solved this problem for them by bringing them to live with her in the Emerald City, as permanent guests of Princess Ozma. Henry was given the job of being Keeper of the Jewels in Ozma's treasure hoard for the purpose of keeping him occupied.
By Glinda of Oz, he has become one of Ozma's closest advisers, having taught his agricultural abilities to Ozite farmers, getting them producing surplus for the Emerald City storehouses.
Uncle Henry has been featured slightly more than Aunt Em in the Oz books, despite being less featured than Auntie Em in the film, The Wizard of Oz (1939). Ruth Plumly Thompson gave him only two brief mentions, in The Royal Book of Oz and Grampa in Oz. He had somewhat larger roles in John R. Neill's The Wonder City of Oz and The Scalawagons of Oz and Jack Snow's The Magical Mimics in Oz.