The quake, which the U.S. Geological Survey (USGS) measured at magnitude 6.8, struck at a depth of 66.4 km (41.3 miles) about 10 km (6.2 miles) from the city of Balao in the province of Guayas.
The earthquake did not appear likely to generate a tsunami, authorities said.
"We remain in the territory verifying the damage caused by the earthquake this morning. I want to confirm that I am with you and express my solidarity and commitment to the victims," Ecuadorian President Guillermo Lasso said in a tweet.
The presidency's communication agency said the quake left 14 people dead, and more than 380 people were injured, largely in the El Oro province.
The agency said at least 44 homes were destroyed, while 90 more were damaged. Around 50 educational buildings and more than 30 health centers were also affected, while multiple roadways were blocked by landslides caused by the earthquake. The Santa Rosa airport suffered minor damage, but remained in operation.
State-run oil company Petroecuador had evacuated and suspended activities in multiple facilities out of precaution, but had not reported damage, the agency said.
"We all ran out into the streets... we were very scared," Ernesto Alvarado, a resident of Isla Puna near the epicenter, told Reuters, adding that some homes had collapsed.
The initial quake was followed by two weaker aftershocks in the following hour, according to the Geophysics Institute of Ecuador.
Peruvian authorities said the quake was felt in the country's northern region, but there were no immediate reports of harm to people or structures.