2 Tycho Brahe(Astronomer)
3 Hans Christian Ørsted(Physicist)
Hans Christian Ørsted was a Danish chemist and physicist. He was the first person to discover that electric currents can be used to create magnetic fields. His discovery was the first relationship found between magnetism and electricity. Oersted, the unit of the auxiliary magnetic field H, is named in his honor.
4 Bjarne Stroustrup(Computer scientist, Engineer, Scientist, Programmer, Writer, University teacher)

Bjarne Stroustrup is a Danish computer scientist best known for his invention and development of the popular C++ general-purpose programming language. He is currently working as a managing director at Morgan Stanley in New York, apart from serving as a visiting professor at the prestigious Columbia University.
5 Hans Christian Gram(Former bacteriologist noted for his development of the Gram stain)

Hans Christian Gram was a Danish bacteriologist best remembered for developing a technique called Gram stain, which is still used today to classify bacteria. He achieved international recognition after developing the Gram stain technique. Hans Christian Gram also served as a professor at the University of Copenhagen.
6 David Heinemeier Hansson(Programmer)

David Heinemeier Hansson is a Danish programmer best known as the creator of the popular Ruby on Rails web development framework. Along with Dave Thomas, he co-wrote Agile Web Development with Rails. He is a partner at the web-based software development firm Basecamp. Also a car racing enthusiast, he took part in the 2012 24 Hours of Le Mans.
7 Aage Bohr(Physicist)
Nobel Prize-winning Danish nuclear physicist Aage Bohr is best remembered for his work related to the geometry of atomic nuclei. Son of Nobel laureate physicist Niels Bohr, Aage had started his career as an assistant to his father and working on the development of the atomic bomb.
8 Rasmus Lerdorf(Co-authored and inspired the PHP scripting language)

Rasmus Lerdorf was the brain behind the PHP scripting language, which flourished from his personal home page and became an open-source language used worldwide. Born in Greenland, he later moved to Denmark, before settling in Canada, and has had a successful stint with companies such as Yahoo! and Etsy.
9 Lene Hau(Physicist)

Lene Hau is a Danish physicist and educator currently serving as the Mallinckrodt Professor of Physics and Applied Physics at Harvard University. She has done major research into novel interactions between ultracold atoms and nanoscopic-scale systems. She also often speaks at international conferences. She is a recipient of the George Ledlie Prize and the Richtmyer Memorial Award.
10 Piet Hein(Polymath)

Piet Hein was a Danish polymath. He was an expert in mathematics and was also an inventor, designer, and writer. He studied at the University of Copenhagen and Technical University of Denmark. He joined the Danish resistance movement when the Germans invaded Denmark. In his later years, he invented the Soma cube and devised the games of Hex and Tower.
11 Nicolas Steno(Scientist)

Nicolas Steno was a 17th-century Danish scientist considered a pioneer in both anatomy and geology. He received training in the classical texts on science and went on to become an expert on fossils and rock formation. Today, he is considered one of the founders of modern stratigraphy and modern geology. He became a Catholic bishop in his later years.
12 Ole Rømer(Astronomer)

Ole Rømer was a Danish astronomer known for making the first quantitative measurements of the speed of light in 1676. Born into a wealthy family where his interest in mathematics and astronomy were encouraged, he went on to study at the University of Copenhagen. He had a high-profile career and was employed by the French government under King Louis XIV.
13 Inge Lehmann(Seismologist)
Danish seismologist Inge Lehmann is remembered for her groundbreaking discovery of the Earth’s solid inner core and molten outer core, using seismic waves. While she initially studied math, she later deviated to seismology, with a focus on ascertaining earthquake epicenters. The William Bowie Medal-winning scientist died at age 104.
14 Peter Naur(Danish astronomer)

Peter Naur was a Danish computer science pioneer. Along with John Backus, he contributed to the development of the Backus–Naur Form (BNF) notation used in describing the syntax for most programming languages. He began his career as an astronomer, eventually shifting to computers. He was a professor of computer science at the University of Copenhagen for many years.
15 Niels Ryberg Finsen(Physician)
Niels Ryberg Finsen was a Danish-Faroese scientist and physician. Finsen's method to treat diseases, such as lupus vulgaris, using concentrated light radiation, earned him the 1903 Nobel Prize in Medicine and Physiology. Copenhagen University Hospital houses the famous Finsen Laboratory, which is named in his honor.
16 Agner Krarup Erlang(Mathematician, Engineer, Statistician)

Agner Krarup Erlang was a Danish mathematician, statistician, and engineer. he graduated from the University of Copenhagen with distinction and worked as a teacher for many years. He is best known for inventing the fields of traffic engineering and queueing theory. He is also credited with the creation of the field of telephone networks analysis.
17 Johannes Nicolaus Brønsted(Chemist)

18 Harald Bohr(Mathematician)

19 Johan Christian Fabricius(Zoologist)

Johan Christian Fabricius was a Danish zoologist. He specialized in "Insecta", which at that time included all insects, arachnids, crustaceans, and other anthropoids. He studied under the renowned Swedish zoologist Carl Linnaeus and went on to become one of the most important entomologists of the 18th century. He is credited to have named nearly 10,000 species of animals.
20 Max Henius(Biochemist)

21 Ben Roy Mottelson(Physicist)
22 Jens Peter Jacobsen(Novelist)

23 August Krogh(Zoophysiologist)
August Krogh was a Danish professor who taught at the University of Copenhagen between 1916 and 1945. He is best remembered for receiving the prestigious Nobel Prize in Physiology or Medicine in 1920. Apart from his contributions to medicine, August Krogh is also remembered for co-founding the popular multinational pharmaceutical company, Novo Nordisk.
24 Jens C Skou(Biochemist)
Jens C. Skou was a Danish biochemist best known for his work in the field of animal cells. Along with Paul D. Boyer and John E. Walker, he was jointly awarded the Nobel Prize in Chemistry in 1997. He had a brilliant academic career and remained active well into his 90s. He died at the age of 99.
25 Wilhelm Ludvig Johannsen(Botanist)

26 Niels Kaj Jerne(Immunologist)

Niels Kaj Jerne was a Danish immunologist best remembered for winning the 1984 Nobel Prize in Physiology or Medicine alongside César Milstein and Georges J. F. Köhler. Jerne, who made important contributions to the fields of Immunology and Microbiology, was also honored with the Marcel Benoist Prize and Paul Ehrlich and Ludwig Darmstaedter Prize in 1978 and 1982 respectively.
27 Thomas Bartholin(Physician)

Thomas Bartholin was a Danish physician, theologian, and mathematician. He is best remembered for discovering the lymphatic system in human beings. Thomas Bartholin is also known as the first person to scientifically describe refrigeration anesthesia, which is widely used today, especially while performing major amputations of the limbs.
28 Ejnar Hertzsprung(Chemist)

29 Johannes Eugenius Bülow Warming(Danish botanist)

30 Henrik Dam(Biochemist)
31 Johannes Fibiger(Physician)

32 Emil Christian Hansen(Mycologist)

33 John Louis Emil Dreyer(Astronomer)

John Louis Emil Dreyer was a Danish astronomer. He is best remembered for serving as the president of the Royal Astronomical Society from 1923 to 1925. Prior to his service as the president John Louis Emil Dreyer was honored with the gold medal, the highest award given by the society, in 1916.
34 Rasmus Bartholin(Physician)

Rasmus Bartholin was a Danish grammarian and physician. He is best remembered for his discovery of the double refraction of a ray of light by Iceland spar. Rasmus Bartholin is also remembered for his association with the University of Copenhagen where he served as a professor of Geometry and Medicine.
35 William Christopher Zeise(Organic Chemist)
36 Peter Andreas Hansen(Astronomer)

Born to a goldsmith, Peter Andreas Hansen had initially learned the art of watchmaking. However, his skills as an astronomer eventually earned him the post of the director of the Seeberg Observatory near Gotha. His best-known works are related to optics, probability theory, and the motion of the Moon.
37 Willi Dansgaard(Paleoclimatologist)

38 Steen Willadsen(Scientist)

39 Christen Sørensen Longomontanus(Astronomer)

Christen Sørensen Longomontanus was a Danish astronomer best remembered for developing Tycho Brahe's geoheliocentric model of the universe. Brahe's geoheliocentric model, which was also known as the Tychonic system, was widely accepted at that time. Christen Sørensen Longomontanus also published major works in astronomy and mathematics such as Systematis Mathematici and Disputatio de Eclipsibus.
40 Hans Peter Jørgen Julius Thomsen(Chemist)

41 Bengt Strömgren(Astronomer)

42 Peter Wilhelm Lund(Paleontologist, Zoologist, Archeologist)

Peter Wilhelm Lund was a Danish paleontologist, zoologist, and archeologist. He spent most of his life working in Brazil and is considered the father of Brazilian paleontology as well as archaeology. He became the first person to describe dozens of species of pre-historic Pleistocene megafauna and discovered the fossilized remains of human beings among the remains of long-extinct species.