The water vapor was found 11.5 billion light years from Earth, using the 100-meter Effelsberg radio telescope at the Max Planck Institute for Radio Astronomy in Leipzig, Germany.
Astronomers say the water vapor is in the form of a disc, called a maser, orbiting a black hole.
Black holes are regions in the universe where gravity is so strong everything around them, including light, is sucked in.
John McKean, who is part of the research team at the Max Planck Institute, says some black holes, are inactive.
And McKean says masers are safe from their gravitation pull, offering astronomers an opportunity to trace the gases swirling around black holes.
"We can actually see the gas rotating around the black hole, and how fast it is rotating depends on how massive the black hole is," he said. "And this is one of the main science goals of studying these water masers in local galaxies. And they really get tremendous results for measuring the masses of black holes."
Violette Impellizzeri, formerly of the Max Planck Institute and now with the National Radio Observatory in Virginia, led the investigation of the ancient water disc. She says the existence of water in a galaxy that is close to the 13-billion-year-old age of the Universe is not unexpected, but it is the first time it has been shown.
"This is also a result by itself, that we were able to find a molecule [water] seemed to have produced after a very short time after the Big Bang," she said. "I mean the Universe is young and already there is already a high abundance of molecules."
The study on the discovery of ancient water in the Universe is published in the journal Nature.