Merzifon stands north-west of Amasya, at the southern foot of Taşan Dağı, on the edge of the wide plain watered by the Tersakan stream and its tributaries the Gümüşsuyu and the Solhan. After the provincial centre it is the most populous district in the province. The highway from Istanbul and Ankara to Samsun crosses here with the old routes running down from Çorum to the Black Sea, and the town's history has been shaped largely by this position at a crossroads.
Settlement on the plain goes back to the Chalcolithic, as the mounds at the villages of Ortaova and Hayrettin show. According to Mehmet Öz, the town was founded on the site of ancient Phazemon, which Pompey renamed Neapolis, and the present name developed through the forms Phamidzon, Mazifon and Mersivan. After Manzikert the Danishmendid İltegin Gazi took the town, and in 1101 a crusading army was routed on the Merzifon plain. The oldest known monument in the town is the Mosque of Muinuddin Pervane, whose inscription of 1265 survives. The four-iwan madrasa built by Çelebi Mehmed in 1414, the tomb of Piri Baba, and the complex of Merzifonlu Kara Mustafa Pasha raised between 1666 and 1679, with its mosque, bedesten and Taşhan, are the town's chief historic buildings. Kara Mustafa Pasha, the grand vizier of the siege of Vienna, was born in the village of Marınca, now called Karamustafapaşa. Anatolia College, founded in the late nineteenth century, and an aviation history going back to the mid-1930s define the town's recent past.
The economy rests on wheat, sugar beet, barley, sunflower and lentils, on cherry and apple orchards, and on the firms of the organised industrial zone set up in 1987. Merzifon keşkek was registered with a geographical indication in 2014. According to TÜİK figures for 2025, the district has 20 neighbourhoods and 70 villages.
