Hennig is both a surname and a given name. Notable people with the name include:
Surname:
Amy Hennig, video game director and writer
Amy Hennig (wrestler) (born 1981), American professional wrestler (daughter of Curt)
Angela Hennig (born 1981), German professional cyclist
Arthur Saxon (born Arthur Hennig, 1878–1921), German strongman and circus performer
Bernard A. Hennig (1917-2014), American philatelist
Carsten Hennig (born 1976), German football player
Curt Hennig (1958–2003), American professional wrestler known as "Mr. Perfect"
Danielle Hennig (born 1990), Canadian field hockey player
Dennis Hennig (1951–1993), Australian pianist
Edward Hennig (1879–1960), American Olympic gymnast
Edwin Hennig (1882-1977), German paleontologist
Gerd Hennig (born 1935), former German soccer referee
Heike Hennig (born 1966), German dancer, choreographer and theatre director
Heinz Hennig (1927–2002), German choral conductor
Joe Hennig (born 1979), American professional wrestler better known by a number of ring names, currently Curtis Axel (son of Curt)
John Hennig (1911-1986), German theologian
Jürgen Hennig (born 1951), German chemist
Klaus Hennig (born 1944), German judo athlete
Klaus-Peter Hennig (born 1947), German Olympic discus thrower
Larry Hennig (born 1936), American professional wrestler known as "The Axe" (father of Curt, grandfather of Joe and Amy)
Mark A. Hennig (born 1965), American horse racing trainer
Oloff Hennig, South African businessman
Ottfried Hennig (1937–1999), German politician
Roland Hennig (born 1967), German Olympic cyclist
Rudolph Hennig previous member of the Legislative Assembly of Alberta
Shelley Hennig (born 1987), Miss Teen USA 2004, and actress from Days of our Lives
Todd Hennig (born 1976), American drummer, formerly for the hardcore punk band Death by Stereo, currently belongs to Nations Afire
Walter Hennig (born 1972), South African businessman
Willi Hennig (1913–1976), German biologist considered the founder of phylogenetic systematics, also known as cladistics
Christine Theiss (née Hennig), (born 1980), German professional kickboxer
Given name:
Hennig Brand (1630–1710), German alchemist who discovered phosphorus in the mid-17th century
Hennig Wichmann (died 1402), 14th-century pirate