Harry Nielsen (born 3 May 1995) is an Australian cricketer, the son of former South Australian cricketer Tim Nielsen.
Nielsen filled in as a wicket-keeper in a tour match for South Africa against Cricket Australia XI in 2016, replacing South African wicket-keeper Quinton de Kock when he was ruled out with a viral infection.
During the 2017–18 season he made his debuts in all three major forms of the game, first-class, one-day and Twenty20 cricket playing for Cricket Australia XI in the JLT One-Day Cup and tour matches, the Adelaide Strikers in the Big Bash League and South Australia in the Sheffield Shield.