The British Geological Survey said a tremor with a magnitude of 2.2 rocked an area about three miles (5km) south-west of Falmouth at around 6pm on Thursday.
In a series of tweets, the BGS highlighted that one member of the public reported the earthquake as a “loud bang from beneath” and that the “windows shook”.
Shortly after the quake struck, those who felt the earth move tweeted their surprise.
Nick de Larrinaga wrote: “Down in West Cornwall and seems we just had an earthquake! Either that or a sonic boom/explosion of some kind.”
And Steve32 posted: “What the hell was that! The whole house shook!”
According to the BGS there are 15 earthquakes in the UK every year.