Madeline Alice O'Neill also Madeleine O'Neill, née Madeline Alice Fisher (born 1867/1868) was a British tennis player.

She was born Madeline Alice Fisher in 1867.

In mixed doubles, she could reach the semifinals with Norman Kidson in 1913.

In 1922, O'Neill took part in the Wimbledon singles for the last time and won two matches.

[1] Then at an age of 54, she is until today the oldest player to ever have won a match at the Wimbledon singles.