Geisler is a surname. Notable people with the surname include:
Alan Geisler (1931–2009), American food chemist, created a red onion sauce used on hot dogs in New York CityBaron Geisler (born 1982), Filipino actor, the son of a Filipina mother and a German American dadBruno Geisler (1857–1945), German ornithologistChristian Geisler (1869–1951), Danish organist and composerDonald Geisler (born 1978), Filipino taekwondo athlete of German-American descentHans Ferdinand Geisler, Luftwaffe commander during World War IIIlse Geisler (born 1941), East German lugerLadi Geisler, Czech musician, famous in post-war GermanyNorman Geisler (born 1932), Christian apologist, co-founder of Southern Evangelical Seminary outside Charlotte, North CarolinaPeter Geisler, German clarinettistRobert Geisler, former Democratic member of the Pennsylvania House of RepresentativesRudolf Geisler (1911–1944), highly decorated Oberstleutnant in the Wehrmacht during World War II