Kota Long Jaafar is a defensive fort and residence built by Long Jaafar in Bukit Gantang, Perak, in 1820. The fort site measures .
The fort was made from bricks and mud, the first such fort in Perak. Its walls are 2.5 meter high and took five years to complete. It acted as a defensive fort during the Siam invasion. Long Jaafar mansion was situated in the middle with a lake called Takungan Menteri at the front.
Long Jaafar died in 1857 and was buried within his fort. He was succeeded by son Ngah Ibrahim