The Houtribdijk is a dike in the Netherlands, built between 1963 and 1975 as part of the Zuiderzee Works, which connects the cities of Lelystad and Enkhuizen. On the west side of the dike is the Markermeer and on the east is the IJsselmeer. The 27-kilometer-long dike was intended for the Markerwaard, but this polder is now unlikely to be constructed.
Although called a dike, the Houtribdijk is actually a dam.
Parts of the dike are known as the Markerwaarddijk and the Lelydijk. It is also frequently called the "Enkhuizen–Lelystad dike" in traffic announcements, as if it had no official name.
The road that runs on the dike is the N302 and is used by 8,500 vehicles per day with a speed limit of 100 km/h. Marine traffic can cross the dike at either the locks or the naviduct at Enkhuizen. Alternatively, there is a lock system at Lelystad.
About halfway along the dike there is Trintelhaven, an emergency harbor. Trintelhaven is also the site of a restaurant and an AM broadcasting station, which operates on 1395 kHz with 20 kW. It uses as antenna a 54-meters-tall free-standing grounded-lattice steel mast, which was built in 1999. The mast carries a wire antenna, which runs up the tower and is fixed to a horizontal cross on the top of the tower.