VLF Transmitter Woodside, Radio transmission facility near Woodside, Victoria, Australia

The VLF Transmitter Woodside is a radio facility in Victoria, Australia, built around a steel lattice mast standing 432 meters tall. The mast was fitted with electrical insulation at the upper guy cables to send very low frequency signals across oceans and continents.

The United States and Australian governments agreed in 1977 to build an Omega navigation transmitter in south-eastern Australia; after protests, the site was moved from New Zealand to Woodside. The mast was completed in 30 days and opened in October 1982, after 3.5 years of construction, and remained the tallest structure in the Southern Hemisphere until its demolition by explosives on 22 April 2015.

The Omega navigation system was used by ships and aircraft around the world to find their position at sea and in the air. The station at Woodside was one of only eight in the world that worked together to form this global network.

The mast was demolished with explosives on 22 April 2015, so nothing of the 432-metre structure remains on site. Transmission equipment from the Omega navigation system is instead on display at the Port Albert Maritime Museum, where the station's hardware can be examined.

Instead of placing the full weight of the mast on ceramic insulators, the electrical insulation was built directly into the upper guy cables themselves. This approach was uncommon among similar transmitters elsewhere in the world.