Which cathedral in France has the highest completed Gothic nave?

Amiens Cathedral has the highest completed Gothic nave, rising about 42.3 metres.

The cathedral was built in the 13th century after a fire destroyed an earlier church. Work began in 1220 under Bishop Evrard de Fouilloy, and the building was largely completed within the century. Its architects used pointed arches, rib vaults, and flying buttresses to create an exceptionally tall and spacious interior.

Amiens stands in Picardy and is dedicated to Saint Firmin, the city’s traditional first bishop. Its west façade is richly decorated with sculpture, while the interior preserves a celebrated sequence of medieval carvings and stained glass.

The building is sometimes confused with Chartres or Reims because all three are major French Gothic cathedrals. Amiens is distinguished here by the height of its completed nave, not by overall length, tower height, or the fame of its sculpture.