The tremor took place at 11.36 pm (0236 GMT), centered off the coast at 42 kilometers (26 miles) west of Valparaiso, according to the US Geological Survey.
It had a depth of 9.8 kilometers.
Chile's National Emergency Office, or ONEMI, estimated its strength at 6.1 on the Richter scale.
However, no warning was issued by the Hawaii-based Pacific Tsunami Warning Center.
A series of smaller earthquakes in Valparaiso in the evening hours rattled locals.