It allows doctors to diagnose and treat cervical cancer early on in the disease's progression. But decades later, a 1998 article on the Pap test described his contribution to women's medical care this way: "This is the story of an ambitious and brilliant man, Georgios Papanikolaou, and his devoted wife, Andromache Mavroyenous, whose discovery of the screening test is now recognized as the most significant advance in the control of cancer in the 20th century".
The doodle, an illustration of him inspecting cells under a microscope, was available in 12 countries around the world.
Google said: "Today's Doodle celebrates Georgios Papanikolaou, the Greek cytopathologist who worked with his wife to develop the life-saving medical test known as the Pap smear".
All this should suggest the direction of work of Georgios Papanikolaou.
Georgios Papanikolaou was born in Kymi, Greece, on 13 May 1883, and studied medicine at the University of Athens after initially pursuing music and the humanities.
Papanikolaou started medical school at age 15, and after graduation served as an army surgeon in the Balkan wars. He graduated in 1904 and six years later received a postgraduate degree from the University of Munich.
When he returned to Greece he married the educated and open-ended Andromachi Mavroyenis.
They initially struggled to get by, with Dr Papanikolaou selling carpets and playing the violin in restaurants while his his wife sewed buttons. With his wife by his side as a technician and sometimes-test-subject, Papanikolaou began studying sex determination in guinea pigs, and quickly found that some cells in the vagina and uterus changed throughout the menstrual cycle. He then co-authored a 1943 book called Diagnosis of Uterine Cancer by the Vaginal Smear.
Based on some estimates the smear test has helped slash the number of fatalities in half.
He is credited to have said: "The first observation of cancer cells in the smear of the uterine cervix was one of the most thrilling experiences of my scientific career".
The revolutionising test saw Georgios he nominated for the Nobel Prize twice.
If you've looked anything up today, you might have wondered why Google's logo features a sketch of a scientist.
He was nominated for the Nobel prize twice and has been featured on a US postage stamp as well as the Greek 10,000 drachma note. He wished to develop the Papanicolaou Cancer Research Institute at the University of Miami, which he did not accomplish. But who was he?