Shaking was felt in the capital of Bogota, 150 miles to the northeast.
The United States Geological Survey said the quake occurred at 11:31 a.m. local time about 30 miles from the regional capital of Popayan.
There were no reports of injuries associated with the jolt.
"Between 25 and 30 homes had some kind of impact,” said the director of the Office of Risk Management, Carlos Ivan Marquez.
Popayan was largely rebuilt after a March 1983 quake that killed at least 250 people.
The quake was the strongest to hit the country since the same region was rocked by a 7.2 magnitude temblor in 2004.