Ad is a first name. It is common in the Netherlands, where it is almost always short for Adrianus or Adriaan. In America it can be short for Adolph, Addison, and others. People with the first name of Ad include:
Ad van der Avoird (born 1943), Dutch chemist
Ad Bax (born 1956), Dutch-American biophysicist
Ad de Boer (born 1946), Dutch politician
Ad Brennan (1887–1962), American baseball pitcher
Ad Carter (1895–1957), American cartoonist (Ad stands for "August Daniel")
Ad Donker (1933–2002), Dutch-South African publisher
Ad Gumbert (1868–1925), American baseball pitcher
Ad Kaland (1922–1995), Dutch politician
Ad van Kempen (born 1944), Dutch actor
Ad Kolnaar (born 1942), Dutch economist
Ad Konings (born 1956), Dutch ichthyologist
Ad Koppejan (born 1962), Dutch politician
Ad Lagendijk (born 1947), Dutch physicist
Ad van Liempt (born 1949), Dutch journalist
Ad Liska (1906–1998), American baseball pitcher
Ad van Luyn (born 1935), Dutch Roman Catholic bishop
Ad Melkert (born 1956), Dutch politician
Ad Moolhuijzen (born 1943), Dutch water polo player
Ad Neeleman (born 1964), Dutch-British linguist
Ad Reinhardt (1913–1967), American abstract painter
Ad Rutschman (born 1931), American football and baseball coach
Ad Santel (1887–1966), American professional wrestler
Ad Simonis (born 1931), Dutch Roman Catholic cardinal
Ad Sluijter (born 1981), Dutch guitarist
Ad Snijders (1929–2010), Dutch painter
Ad van der Steur (1893–1953), Dutch architect
Ad Swigler (1895–1975), American baseball pitcher
Ad Tak (born 1953), Dutch bicycle racer
Ad van Tiggelen (born 1958), Dutch banker and fantasy writer
Ad Vandenberg (born 1954), Dutch rock guitarist
Ad Wenke (1898–1961), American football player and justice
Ad Wijnands (born 1959), Dutch bicycle racer
Ad Wolgast (1888–1955), American boxer
Ad Yale (1870–1948), American baseball player
