John Willian, Jr. (1835 – April 25, 1869) was an American Union brevet brigadier general during the period of the American Civil War. Born in Lancashire, he was one of the few higher-ranked Civil War officers to be born in England. He served as a second lieutenant with the 4th New Jersey Militia during the time of the First Battle of Bull Run. He served as acting assistant inspector general for Brigadier General Gershom Mott and later for Major General Andrew A. Humphreys. He received his appointment as brevet brigadier general dated to April 9, 1865.