23 June is the 174th day of the year (175th in leap years). There are 191 days remaining until the end of the year.
- 1906: Dinah Stevenson dies.
- 1980: Dudley Dursley is born to Vernon and Petunia Dursley (née Evans).
- 1991: The Dursleys, Harry Potter and Piers Polkiss have a trip to the Zoo, commemorating Dudley's eleventh birthday. Harry speaks Parseltongue for the first time with a Boa constrictor.