McKennan is a surname of Irish origin. It may refer to:
John T. McKennan (1918–2011), New York politician Peter McKennan (1918–1991), Scottish footballer Thomas McKean Thompson McKennan (1794–1852), US congressman from Pennsylvania, US Secretary of the Interior William McKennan (1816–1893), United States federal judge
See also McKennan Pomeroy (born 2002), Cherokee American singer-songwriter better known as Ken Pomeroy McKenna (name)