According to the scientists, the black hole, identified as M87, is as large as the orbit of Neptune and by far the largest and most distant galaxy in the nearby universe.
As a point of comparison, the black hole at the centre of the Milky Way is 1,000 times smaller than this one which has been observed some 50 million light years away.
A black hole is a region of space from which nothing, not even light, can escape. It is the result of the deformation of spacetime caused by a very compact mass.
Scientists, who used a specially adapted telescope in Hawaii to observe M87, believe that it is more than twice as heavy as had been previously thought, catapulting it into the record books, the Daily Mail reported.
The researchers said that it may have formed as a result of hundreds of smaller black holes merging into one at some point in the past.
Speaking about the discovery, astronomer Karl Gebhardt of the University of Texas in Austin said: "It could swallow our solar system whole."
Astronomer George Djorgovski, of the California Institute of Technology in Pasadena, who was also involved in the research, added that the chance to study such huge black holes are not just a curio for the record books.
He said: "In fact, future observations of this object might finally help us prove that what we call black holes are really black holes.
"Until now, there has been no direct observational evidence at all for the existence of event horizons, which are the true signatures of black holes."
According to Prof Gebhardt, the discovery was made using the adaptive optics capability of the 8.1-metre Frederick C Gillett Gemini Telescope on Mauna Kea, Hawaii.
He and his team were able to track stars orbiting the black hole at up to 500km per second, which allowed them to work out its mass.
"It`s the most accurate mass estimate ever obtained for a supermassive black hole," he said.
Previous estimates had M87 as only three billion times the weight of the sun.
Despite the discovery, the record looks unlikely to stand for long as over the coming decade astronomers plan to link up telescopes all over the world to create a giant array that will significantly increase their ability to find and observe black holes.