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.
The Navy's hydrographic and oceanographic service found that the earthquake "has the characteristics to generate a tsunami".
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.