The following articles contain lists of notable problems. This includes unsolved problems, which may refer to several notable conjectures or open problems in various academic fields:

Natural sciences and medicine

• List of unsolved problems in astronomy

• List of unsolved problems in biology

• List of unsolved problems in chemistry

• List of unsolved problems in geoscience

• List of unsolved problems in medicine

• List of unsolved problems in neuroscience

• List of unsolved problems in physics

Mathematics

• List of unsolved problems in mathematics

• List of undecidable problems

• List of NP-complete problems

• List of PSPACE-complete problems

• List of problems in loop theory and quasigroup theory

Social sciences, statistics, and information sciences

• List of unsolved problems in economics

• List of unsolved problems in fair division

• List of unsolved problems in statistics

• List of unsolved problems in computer science

• List of unsolved problems in information theory

Other

• List of philosophical problems

• List of unsolved deaths

See also

• Cold case

• List of ciphertexts

• List of hypothetical technologies

• List of paradoxes

• Unknowability