The bombs were 330-pound American and British bombs.
Investigators said they initially thought they had detected four bombs, but later clarified that only two were found.
Crews evacuated two hospitals and opened schools for people who had to leave their homes. City officials had asked about 14,000 people to leave the areas where the bombs were buried.
Officials also shut down Dortmund’s train station and rerouted trains.
Helicopters patrolled overhead to ensure everyone had evacuated before experts defused the two bombs.
Unexploded bombs in Germany followed by evacuations have been a familiar scenario since the end of World War II nearly 75 years ago.
Last summer, a 1,100-pound World War II bomb was defused in Frankfurt after 16,500 people were called on to leave their homes.
The Associated Press contributed to this report.