Osborne Reef is an artificial reef off the coast of Fort Lauderdale, Florida at 26°06′27″N 80°03′54″W / 26.10748°N 80.06493°W / 26.10748; -80.06493. Originally constructed of concrete jacks, it was the subject of an ambitious expansion project utilizing old and discarded tires. The expansion ultimately failed, and the reef has come to be considered an environmental disaster—ultimately doing more harm than good in the coastal Florida waters.

In 2007, after several false starts, cleanup efforts began when the United States military took on the project. This cleanup exercise provided the military with a real-world training environment for their diving and recovery personnel, coupled with the benefit of helping the Florida coast without incurring significant costs to the state. In 2015, a civilian corporation took over, and had removed one third of the tires by November 2019.

The reef was originally constructed of concrete jacks in a 50-foot (15 m) diameter circle.

In 1972, Broward Artificial Reef Inc. (BARINC) proposed the construction of an enlarged artificial reef to Broward County as a way to both dispose of old tires and lure more game fish to the area. Similarly designed reefs had already been constructed in the Northeastern United States, the neighboring Gulf of Mexico, Indonesia, Malaysia, Australia, and Africa. Gregory McIntosh, a BARINC employee, lauded the project to the attendees of a 1974 conference on artificial reefs: "Tires, which were an esthetic pollutant ashore, could be recycled, so to speak, to build a fishing reef at sea."

With endorsement of the project by the US Army Corps of Engineers, the Broward County government approved the project in 1974. That spring, more than 100 privately owned boats enthusiastically volunteered to assist with the project; accompanied by the US Navy's USS Thrush, thousands of tire bundles were simultaneously dropped onto the reef. The Goodyear Tire and Rubber Company provided equipment for the auspicious undertaking, even supporting the project so far as to drop a gold-painted tire from a Goodyear Blimp to christen the site. The culmination of the project was the deposit of over two million tires bound with steel clips over 36 acres (15 ha) of the ocean floor, approximately 7,000 feet (2,100 m) offshore, and at a depth of 65 feet (20 m).

The really good idea was to provide habitat for marine critters so we could double or triple marine life in the area, [...] It just didn't work that way. I look back now and see it was a bad idea.

Ultimately, little marine life has been successful in latching onto the man-made reef and the majority never had the opportunity to do so. While a few tires were individual loose entities, the majority were bound together with nylon or steel clips (or bands). As there were no exceptional efforts made to ensure the non-corrodibility of the steel restraints, they summarily failed—resulting in the loosing of over two million individual, lightweight tires.

This newfound mobility destroyed any marine life that had thus far grown on the tires, and effectively prevented the growth of any new organisms. Furthermore, the tires were now easily subject to the tropical winds and storms that frequent the east coast of Florida, and continue to collide, at times with tremendous force, with natural coral reefs only 70 feet (21 m) away: compounding their futility with environmentally damaging side-effects. Lastly, the concern of adjacent coastal areas is that the tires are not remaining within the boundaries of Osborne Reef.