Mike Hennessey (25 February 1928 – 16 August 2017) was an English music journalist and jazz pianist. Born in London as the third of four children, Hennessey, who came from a musical family, began learning piano at the age of six. After his military service, he began working as a journalist. He has written for many jazz magazines in Europe and North America and worked for 27 years as a correspondent and international editor for the US magazine Billboard, before retiring in 1994. He specialised in international copyright and intellectual property, and advocated strengthening of copyright protection for the music industry. He also co-founded international industry magazines such as Music Week and Music & Media, and wrote books on the music business and biographies of jazz musicians Kenny Clarke and Johnny Griffin. As a pianist he was a membber of Chas Burchell's band, with which he recorded two albums. He also joined the Paris Reunion band with Nat Adderley, toured with Adderley, Billy Mitchell, Arthur Blythe, Benny Golson, Keter Betts, Jimmy Cobb, and Jan Harrington, and worked as an accompanist for Buddy DeFranco, Nathan Davis, Johnny Griffin, Duško Gojković, and Ronnie Scott.He moved to Germany and lived in Durchhausen from 1998 until his death in 2017 after a brief illness. He was survived by his wife, the German concert agent Gaby Kleinschmidt.