O'Day

O'Day is a surname of Irish origin. Notable people with the surname include:


 * Alan O'Day (1940–2013), American singer-songwriter
 * Anita O'Day (1919–2006), American jazz singer
 * Aubrey O'Day (born 1984), American singer, dancer, actress, songwriter, fashion designer, former member of the group Danity Kane
 * Caroline Love Goodwin O'Day (1875–1943), American politician
 * Constance O'Day-Flannery, an American author of romance novels
 * Daniel O'Day, one of northwestern Pennsylvania's earliest independent refiners to be brought into John D. Rockefeller's Standard Oil Company
 * Daniel O'Day, Chairman and Chief Executive Officer, Gilead Sciences
 * Darren O'Day (born 1982), Major League Baseball relief pitcher for the Atlanta Braves. Real last name Odachowski, not Irish.
 * George O'Day (1923–1987), American sailor, Olympic champion and boat designer
 * Hank O'Day (1859–1935), American right-handed pitcher, umpire and manager in Major League Baseball
 * Jeremy O'Day (born 1974), offensive lineman for the Saskatchewan Roughriders of the Canadian Football League
 * John O'Day (1856–1933), American politician
 * Marcus O'Day (1897–1961), American physicist
 * Molly O'Day (1911–1998), American film actress
 * Molly O'Day (singer) (1923–1987), American country music vocalist in the late 1940s
 * Nell O'Day (1909–1989), accomplished equestrian and B-movie actress of the 1930s and 1940s
 * Pat O'Day (born 1934), Pacific Northwest broadcaster and promoter