John McGrath may refer to:

• John J. McGrath (1872–1951), U.S. Representative from California
• John McGrath (New South Wales politician) (1893–1971), Labor member of the New South Wales Legislative Assembly
• John McGrath (Victorian politician) (1939–2021), National member of the Victorian Legislative Assembly
• John McGrath (Western Australian politician) (born 1947), Liberal member of the Western Australian Legislative Assembly

• John McGrath (footballer, born 1932) (born 1932), football inside forward (Notts County and Darlington 1955–59)
• John McGrath (footballer, born 1938) (1938–1998), English football centre half (Bury, Newcastle and Southampton 1955–73), later manager
• John McGrath (Irish footballer) (born 1980), Irish footballer
• John-Alan "Jay" McGrath (born 2003), Irish footballer

• John McGrath (Tipperary hurler) (born 1994), Irish hurler
• John McGrath (Westmeath hurler) (1928–1980), Irish hurler

• John McGrath (shot putter), winner of the 1966 USA Indoor Track and Field Championships
• Jack McGrath (racing driver) (1919–1955), American racecar driver
• John McGrath (ice hockey), Canadian ice hockey player and political advisor

• John McGrath (artistic director) (born 1962), British artistic director and CEO of Manchester International Festival
• John McGrath (playwright) (1935–2002), Liverpudlian-Irish playwright

• John McGrath (entrepreneur), Australian businessperson
• John W. McGrath (1842–1905), American jurist
• Denis McGrath (lawyer) (1910–1986), New Zealand lawyer and politician
• Sir John McGrath (judge) (1945–2018), judge of the Supreme Court of New Zealand
• John McGrath (POW),

• John Magrath (disambiguation)