She sailed up Belfast Lough into Belfast Harbour on Saturday morning to visit her adopted city.
The gangplank was down on Sunday for the public to visit, through tickets distributed by Visit Belfast Welcome Centre.
HMS Duncan is affiliated to both Belfast and Dundee and serves as an ambassador for Belfast when deployed globally.
HMS Duncan Stats
- 152m (498ft) long
- Crew of 180 and can carry 60 troops
- Equipped with Sea Viper anti-air missiles
- Flight deck accommodates Chinook helicopter
- Will be in use until 2040
Commander James Stride said:
"This is our first visit to our adopted city and it is fitting that it is one of our first destinations since being formally accepted into the fleet."