Komarov was born on 16 March 1927 in Moscow and grew up with his half-sister Matilda (born in 1915). His father was a labourer who worked at various low-paid jobs to support the family. In 1935, Komarov began his formal education in the local elementary school. Here he showed a natural aptitude for mathematics. In 1941, Komarov left school because of World War II and the German invasion of the Soviet Union, and he became a laborer on a collective farm. He showed an interest in aeronautics from an early age, and he collected magazines and pictures about aviation, in addition to making model aircraft and his own propeller. At the age of fifteen in 1942, Komarov entered the “1st Moscow Special Air Force School” to pursue his dream of becoming an aviator. Shortly thereafter, his family learned that Komarov’s father had been killed in an “unknown war action”. Of necessity because of the German invasion, the flight school was soon moved to the Tyumen region in Siberia for the duration of the war. Students there learned a wide variety of subjects besides aviation—including zoology and foreign languages. In 1945, Komarov graduated from flight school with honors. World War II hostilities ended before Komarov was called on to enter combat.

In 1946, Komarov completed his first year of training at the Chkalov Higher Air Force School in Borisoglebsk in Voronezh Oblast. He then completed his training at the A.K. Serov Military Aviation College in Bataisk. Komarov’s mother died in 1948, seven months before his graduation in 1949, at which he received his pilot’s wings and commission as a lieutenant in the Soviet Air Force.

In December 1949, Komarov served as the pilot of a fighter plane with the 383rd Regiment of the 42nd North Caucasian Fighter Air Division that was based in Grozny.

Komarov married Valentina Yakovlevna Kiselyova in October 1950. He was promoted to senior lieutenant in 1952, and he was later assigned as the chief pilot of the 486th Fighter Aviation Regiment of the 279th Fighter Air Division in the Prikarpate Region. Komarov continued to fly in that position until 1954, and then he enrolled in an engineering course at the Zhukovsky Air Force Engineering Academy. In 1959, Komarov was promoted to the rank of senior engineer-lieutenant. Later that year he achieved his goal of becoming a test pilot at the Central Scientific Research Institute at Chkalovsky.

In September 1959, Komarov was promoted to engineer-captain and invited to participate in the selection process for cosmonaut candidate along with approximately 3,000 other pilots. He was one of twenty candidates selected for “Air Force Group One”; he and the others reported to the newly formed TsPK just outside Moscow for assignment on 13 March 1960.

Shortly after beginning his training Komarov was hospitalised for a minor operation in May 1960, which left him medically unfit for physical training for approximately six months. At the time, the selection criteria placed a heavy emphasis on the physical condition of cosmonauts and any imperfection led to instant disqualification. Since Komarov already held engineering qualifications, he was allowed to remain in the program after assuring the administration he would be able to catch up. He continued with the required academic studies while recovering. He returned to training in October, because his recovery was more rapid than medical staff had expected. During that time he assisted his younger peers with their academic studies; earning him the casual nickname of “The Professor,” which he shared with Belyayev, who was two years his senior. In 1961 the first space flights began. By 1962, Komarov was the third-highest-paid cosmonaut, due to his qualifications, rank and experience. He earned 528 rubles a month, with only cosmonauts 1 and 2, Yuri Gagarin and Gherman Titov, being more highly paid.

When Georgi Shonin demonstrated an unacceptable level of g-force susceptibility in the centrifuge he was replaced by Komarov in May 1962 for planned dual Vostok missions. Komarov was selected as back up for Pavel Popovich (Vostok 4), but subsequent routine ECG testing of Komarov revealed a heart irregularity and he was pulled from the program and replaced by Boris Volynov. The same heart irregularity grounded American astronaut Deke Slayton. After Komarov persistently lobbied medical and military personnel for re-admittance to the program, they allowed him to return to training.

In 1963, cosmonaut training was conducted in six Groups, with Komarov being selected in Group 2 with Valery Bykovsky and Volynov. This group was to train for missions of up to five days in duration scheduled for the latter part of 1963. In May 1963 Alekseyev proposed to General Kamanin that Komarov be named backup for Vostok 5 rather than Khrunov because his suit was ready. Komarov was later named in a further group for planned missions in 1964 with Belyaev, Shonin, Khrunov, Zaikin, Gorbatko, Volynov, and Leonov. The training groups were formed for later Vostok missions (Vostok 7–13), but no actual crews were assigned and the missions did not occur under the auspices of the original Vostok program. In December 1963, Komarov was shortlisted for flight by Kamanin with Volynov and Leonov, having completed two years of training.

In April 1964 Komarov was declared space-flight ready with Bykovsky, Popovich, Titov, Volynov, Leonov, Khrunov, Belyayev, and Lev Demin. From this group the commander of the planned Voskhod mission scheduled for late 1964 would be chosen. In May the group was reduced to Volynov, Komarov, Leonov and Khrunov.

By July 1964, only seven cosmonauts remained eligible for the Voskhod crew after some were disqualified on medical grounds. On 6 July, Komarov was named as the commander of the back-up crew for Voskhod 1. After much heated debate over several months about the selection of the crew between Nikolai Kamanin and Sergei Korolev, Komarov was named as prime crew commander on 4 October 1964, by the State Commission; just eight days before its scheduled launch. Kamanin played tennis with the Voskhod crew that evening and noted that Komarov played poorly in comparison to his crew: Boris Yegorov and Konstantin Feoktistov.

In December 1964, the RVSN (Strategic Rocket Forces) requested that Komarov be transferred from the VVS (Soviet Air Force) to the RVSN, in a move possibly motivated by the poor record of the RVSN in producing successful rockets compared to the VVS. The request was opposed by Kamanin.

In 1965, Komarov worked with Yuri Gagarin in supervising preparations for the flight of Voskhod 2, which carried out the first attempt of an extravehicular activity in outer space. These preparations included fitting of space suits on the cosmonauts and briefings for the spaceflight. In April of that year, Komarov toured Leningrad with Kamanin, Gagarin, Gherman Titov, Belyayev, and Leonov. Komarov also visited Petropavlovsk Fortress with Valentin Glushko where Glushko had conducted early rocket experiments in the early 1930s. In September that year, Komarov toured West Germany.

Komarov was assigned to the Soviet Soyuz program along with Yuri Gagarin and Alexei Leonov. In July 1966, Komarov was reprimanded by Kamanin for his unauthorised disclosure, while in Japan, that “the Soviet Union will, at the scheduled time, fly an automated spacecraft around the Moon and return it to (the) Earth, to be followed by a dog flight, then a manned circumlunar flight.” The following month Komarov clashed with other engineers over ongoing design problems in which zero-G tests showed that the Soyuz module hatch was too small to allow the safe exit of a fully suited cosmonaut. Meanwhile, Komarov and his fellow cosmonauts had their groups and assignments constantly revised, and they became increasingly anxious about the lack of response to their concerns about the design and manufacture of the spacecraft, which Yuri Gagarin had raised in a letter on their behalf to Leonid Brezhnev.

Komarov was selected to command the Soyuz 1, in 1967, with Yuri Gagarin as his backup cosmonaut. The cosmonauts knew that the spacecraft had major safety problems, but Komarov stated that if he were to refuse to fly, Gagarin would be forced to go instead. Komarov chose to fly to protect Gagarin, and insisted before the flight that his funeral be open-casket so that the Soviet leadership could see what they had done. During the preparations for the spaceflight, both cosmonauts were working twelve- to fourteen-hour days. On orbital insertion, the solar panels of the Soyuz module failed to fully deploy thereby preventing the craft from being fully powered and obscuring some of the navigation equipment. Komarov reported: “Conditions are poor. The cabin parameters are normal, but the left solar panel didn’t deploy. The electrical bus is at only 13 to 14 amperes. The HF (high frequency) communications are not working. I cannot orient the spacecraft to the sun. I tried orienting the spacecraft manually using the DO-1 orientation engines, but the pressure remaining on the DO-1 has gone down to 180.” Komarov tried unsuccessfully to orient the Soyuz module for five hours. The craft was transmitting unreliable status information, and lost communications on orbits 13 through 15 due to the failure of the high frequency transmitter that should have maintained radio contact while the craft was out of range of the ultra high frequency (UHF) ground receivers.

When interviewed on 17 May by the newspaper Komsomolskaya Pravda, Yuri Gagarin alluded to the failure of the administration to listen to the concerns about the Soyuz module that the cosmonaut corps had identified, and maintained that Komarov’s death should teach the establishment to be more rigorous in its testing and evaluation of “all the mechanisms of the spaceship, even more attentive to all stages of checking and testing, even more vigilant in our encounter with the unknown. He has shown us how dangerous the pathway to space is. His flight and his death will teach us courage.” In May 1967, Gagarin and Leonov criticised program head Vasily Mishin’s “poor knowledge of the Soyuz spacecraft and the details of its operation, his lack of cooperation in working with the cosmonauts in flight and training activities,” and asked Kamanin to cite him in the official crash report.

On 26 April 1967, Komarov was given a state funeral in Moscow, and his ashes were interred in the Kremlin Wall Necropolis at Red Square. The American astronauts requested the Soviet government to allow a representative to attend, but were turned down.

On 25 April 1968, a memorial service was held for Komarov at the crash site near Orsk 51°21′41.67″N 59°33′44.75″E / 51.3615750°N 59.5624306°E / 51.3615750; 59.5624306. Kamanin noted in his diary that over 10,000 people were present at this service, “some driving hundreds of kilometres for the event.”

Before leaving the Moon on Apollo 11’s Lunar Module, Neil Armstrong’s final task was to place a small package of memorial items to honor Soviet cosmonauts Komarov, Yuri Gagarin, and the Apollo 1 astronauts Gus Grissom, Ed White, and Roger Chaffee. Komarov’s name also appears on a commemorative plaque left at Hadley Rille on the Moon by the commander of Apollo 15, David Scott in memory of 14 deceased NASA astronauts and USSR cosmonauts, along with a small sculpture entitled Fallen Astronaut, on 1 August 1971. This plaque and the sculpture represent those astronauts and cosmonauts who died in the quest to reach outer space and the Moon.