Spanish authorities say Canada is among 34 countries with citizens killed or injured in the terrorist attack in Barcelona.
Global Affairs says Canadians have been affected by the attacks, but did not provide further details, citing privacy reasons.
Canadians in Spain are advised to stay away from the Las Ramblas tourist area in Barcelona where an alleged terrorist drove a van into a crowd, killing at least 13 people and injuring more than 100.
A second attack occurred in the resort town of Cambrils south of Barcelona eight hours later, leaving one woman dead.
Global Affairs spokesman Austin Jean says the government is in contact with family members of Canadians affected by the attacks and is trying to gather more information.
"Our thoughts are with the Canadians who were affected by the terrorist attack that occurred in Barcelona," Jean said in a statement.
The department urged Canadians in Spain to let their loved ones know they are safe.
Prime Minister Justin Trudeau said in a statement Thursday that he was "deeply saddened" by the news.
"While we cannot ignore the outrage we feel, together we must renew our commitment to protect the freedom found in societies that promote unity, openness and inclusion," wrote Trudeau, who has been out of the spotlight on a family vacation in British Columbia this week.
"Spain, we grieve with you and denounce hate and violence in all of its forms. Canada will continue working with the international community to fight terrorism and build a world where we can all feel safe and secure."
Spanish authorities said the back-to-back vehicle attacks — as well as an explosion earlier this week in a house elsewhere in Catalonia — were related and the work of a large terrorist group. Four people were arrested in connection with the attacks.
Amid heavy security, Barcelona tried to move forward Friday, with its iconic Las Ramblas promenade quietly reopening to the public and King Felipe VI and Prime Minister Mariano Rajoy joining thousands of residents and visitors in observing a minute of silence in the city's main square.
"I am not afraid! I am not afraid!" the crowd chanted in Catalan amid applause.
— with files from the Associated Press