The European Mediterranean Seismological Centre said the quake struck at a depth of two kilometres. The Geodynamic Institute in Athens added that the earthquake had occurred undersea off the eastern coast of the island.
There were no immediate reports of any damage.
One Brit in Crete said all was fine following the earthquake, adding that it felt like a “weird swaying of the ground”. She said: “Friends who live on Kos felt it too. It was centred just off Crete apparently.”
Writing on the European Mediterranean Seismological Centre website, one resident, from the town of Analipsi near Heraklion, said: “Massive tremor. The whole house shook side to side by at least 15 cms. It lasted about 20 seconds.”
Another resident of the same area said: “Long duration, even people driving felt it.”