O'Day
O'Day is a family name for the following people:
- Alan O'Day (1940–2013), American singer, songwriter and composer
- Anita O'Day (1919–2006), American jazz singer
- Aubrey O'Day (* 1984), American singer and actress
- Caroline Love Goodwin O'Day (1875–1943), American politician
- Molly O'Day (1923–1987), American country singer
