Professor Trilokeshwar Shonku (Bengali: প্রফেসর শঙ্কু) is a fictional scientist and inventor created by Satyajit Ray in a series of Bengali science fiction books of the same name published from 1965 on. He is the central protagonist of the series. Professor Shonku resides in Giridih. His house contains a laboratory, and he lives with his pet cat, Newton, named after Sir Isaac Newton and his man-servant, Prahlad. He was born in the year of 1911 on 16th June but his year of death is unknown.

Professor Trilokeshwar Shonku (known popularly as Professor Shonku) is the protagonist of Satyajit Ray's series "The Adventures of Professor Shonku."

The first story of the series introduced him, in "ব্যোমযাত্রীর ডায়রি" (Byomjatrir Diary).

Professor Shonku's father Tripureshwar was a physician. Professor Shonku was born on 16 June 1911. His nickname is Tilu. Professor Shonku passed matriculation examination of the University of Calcutta at the age of 12. At the age of 16, Professor Shonku received his BSc degree with honours in two subjects, Physics and Chemistry. In Satyajit Ray's last finished novel of the series, Swarnaparnee, that was initially published in the Special Puja issue of Anandamela children's magazine in 1992, it was mentioned that at the age of 20, Professor Shonku took his first job as a professor of physics in Calcutta's Scottish Church College.

Professor Shonku is a polyglot who knows 69 languages. His pet cat 'Newton' is 24 years old.

Ray admitted that he had based Prof. Shonku on the character Professor Challenger, by Arthur Conan Doyle, and a character created by Ray's father Sukumar Ray named Hesoram Hushiar. Ray himself described Shonku as a “mild-mannered Professor Challenger”.

(This list may be incomplete.)

Professor Shonku had many adventures, in both real and fantastical places, some with historical leanings and some with great revelations connected to human civilisation.