Lovell was born at Oldland Common and received his PhD in 1936 from the University of Bristol; in the same year was appointed as a lecturer in physics at the University of Manchester. In 1945, after war service on the development of radar, he returned to Manchester. He was elected in 1951 to the chair of radio astronomy and the directorship of Jodrell Bank (now the Nuffield Radio Astronomy Laboratories), a post he held until his retirement in 1981. He was knighted in 1961.

Lovell's first research was done in the field of cosmic rays. In the course of his work during World War II he realized that radio waves were a possible tool with which to pursue his studies. Thus in 1945 two trailers of radar equipment that had been used in wartime defense work were parked in a field at Jodrell Bank in Cheshire to begin radio investigation of cosmic rays, meteors, and comets. Lovell soon produced worthwhile results on meteor velocities and other topics and began to feel that a more permanent and ambitious telescope should be built.

Thus Lovell began a heroic ten-year struggle to finance a 250-foot (76-m) steerable radio telescope with a parabolic dish that would be able to receive radio waves as short as 30 centimeters. The main problem was to find sufficient funds to meet the rising costs of the project at times of government cuts. Thus in 1955 the project found itself £250,000 in debt. The Department of Scientific and Industrial Research agreed to find half if Lovell could raise the rest. A public appeal failed to raise more than £65,000 and it required a strong public press campaign to move the Treasury to meet the outstanding costs in 1960, three years after the telescope was first used.

The Jodrell Bank telescope came to public notice when it was used to track the first Sputnik in 1957. It was not just an adjunct to the space program, however, but a major tool for astronomical research of which Lovell has given a full account in his Out of the Zenith (1973). He there showed the power of the giant telescope to supplement and advance the discoveries of others. Thus it was the Cambridge radio astronomers under Antony Hewish who discovered pulsars, but they were limited to observing them only for the few minutes each day that the pulsars were on the Cambridge meridian. The steerable Jodrell Bank telescope could observe objects for as long as they were above the horizon and it was no accident that of the 50 pulsars discovered in the northern hemisphere before 1972, 27 were detected at Jodrell Bank. So too with those other mysterious phenomena of the 1960s, quasars. Once more the initial discovery was made elsewhere but Jodrell Bank possessed the instruments to show that some quasars had angular diameters of one second of arc or less, which was surprisingly small for such prodigious sources of energy.

Lovell wrote a number of important books recounting the story – political, financial and scientific – of Jodrell Bank. They include The Story of Jodrell Bank (1968), The Jodrell Bank Telescopes (1985), and his autobiography Astronomer by Chance (1996).