The Gaganyaan mission aims to send three astronauts to an orbit of 400km and bring them back after three days.
India’s space agency Isro has been carrying out a number of tests to prepare for the flight.
In October, a key test demonstrated that the crew could safely escape the rocket in case it malfunctioned.
After its success, Isro said a test flight would take a robot into space in 2024, before astronauts are sent into space in 2025.
At a function at the Isro centre in the southern city of Thiruvananthapuram (formerly Trivandrum) on Tuesday, the four astronaut-designates were described as “dreamers, adventurers and valiant men preparing to go into space”.
The officers, chosen from the Indian Air Force, were introduced as Group Captain Prashanth Balakrishnan Nair, Group Captain Ajit Krishnan, Group Captain Angad Pratap and Wing Commander Shubhanshu Shukla.
Prime Minister Narendra Modi and Isro chief S Somanath pinned badges with golden wings onto their shirts and Mr Modi described them as “India’s pride”.
“These are not just four names or four people. They are four powers who will carry the aspirations of 1.4 billion Indians to space. I congratulate and wish them all the best,” he said.
Officials said the men were selected from a pool of Air Force pilots and had undergone extensive physical and psychological tests before being shortlisted.
They have undergone rigorous training for 13 months in Russia and are now carrying on with their gruelling schedule back home. A video screened at the event showed them working out in the gym, swimming and doing yoga.