El Fadrí is a bell tower in the city of Castellón de la Plana, Spain. It is municipally owned and is characterised by the fact that it is separate from the cathedral, unlike other bell towers that are integrated into the same ecclesiastical building. It is located in the Plaza Mayor, in the centre of the city, next to the church of Santa María and the town hall. Its name comes from this very reason: fadrí means "single" in Valencian, referring to the fact that it is alone and separate from the cathedral.

It is a building built in the Valencian Gothic style, with an octagonal floor plan and four sections that correspond to the clock chamber, the prison, the bell ringer's living quarters and the bell chamber (it has eight swinging bells and three fixed bells located in the spire to signal the quarter and hour). Finally, there is a terrace topped by a small temple. Inside, there is a narrow spiral staircase that provides access to each of the floors. It is about 58 metres high.

Work began in 1440. In 1457 the master builder Saera intervened, building approximately the first section. After a long standstill and several proposals, in 1593 Francisco Galiança de la Lancha, Guillem del Rei, Pedro Crosali, Marc Volsanys, Antonio and Joan Saura intervened and finished the tower, according to the plans presented by the Portuguese Damián Méndez in 1591.

In fact, the Fadrí is currently the symbol of the city of Castellón.