The Great Pacific Garbage Patch (also Pacific trash vortex and North Pacific Garbage Patch) is a garbage patch, a gyre of marine debris particles, in the central North Pacific Ocean. It is located roughly from 135°W to 155°W and 35°N to 42°N. The collection of plastic and floating trash originates from the Pacific Rim, including countries in Asia, North America, and South America.

Despite the common public perception of the patch existing as giant islands of floating garbage, its low density (4 particles per cubic metre (3.1/cu yd)) prevents detection by satellite imagery, or even by casual boaters or divers in the area. This is because the patch is a widely dispersed area consisting primarily of suspended "fingernail-sized or smaller"—often microscopic—particles in the upper water column known as microplastics.

Researchers from the Ocean Cleanup project claimed that the patch covers 1.6 million square kilometres (620,000 square miles) consisting of 45,000–129,000 metric tons (50,000–142,000 short tons) of plastic as of 2018, later growing to twice the size of Texas. By the end of 2024, the Ocean Cleanup had removed more than one million pounds of trash from the Great Pacific Garbage Patch, or 0.5% of the total accumulated trash. While microplastics dominate the area by count, 92% of the mass of the patch consists of larger objects. Some of the plastic is over 50 years old, and includes items (and fragments of items) such as "plastic lighters, toothbrushes, water bottles, pens, baby bottles, cell phones, plastic bags, and nurdles".

Research indicates that the patch is rapidly accumulating. The patch is believed to have increased "10-fold each decade" since 1945. The gyre contains approximately six pounds of plastic for every pound of plankton. A similar patch of floating plastic debris is found in the Atlantic Ocean, called the North Atlantic garbage patch.

The patch was predicted in a 1988 paper published by the National Oceanic and Atmospheric Administration (NOAA). The description was based on research by several Alaska-based researchers in 1988 who measured neustonic plastic in the North Pacific Ocean. Researchers found relatively high concentrations of marine debris accumulating in regions governed by ocean currents. Extrapolating from findings in the Sea of Japan, the researchers hypothesized that similar conditions would occur in other parts of the Pacific where prevailing currents were favorable to the creation of relatively stable waters. They specifically indicated the North Pacific Gyre.

Charles J. Moore, returning home through the North Pacific Gyre after competing in the Transpacific Yacht Race in 1997, claimed to have come upon an enormous stretch of floating debris. Moore alerted the oceanographer Curtis Ebbesmeyer, who subsequently dubbed the region the "Eastern Garbage Patch" (EGP). The area is frequently featured in media reports as an exceptional example of marine pollution.

The JUNK Raft Project was a 2008 trans-Pacific sailing voyage made to highlight the plastic in the patch, organized by the Algalita Marine Research Foundation.

In 2009, two project vessels from Project Kaisei/Ocean Voyages Institute, the New Horizon and the Kaisei, embarked on a voyage to research the patch and determine the feasibility of commercial scale collection and recycling. The Scripps Institute of Oceanography's 2009 SEAPLEX expedition in part funded by Ocean Voyages Institute/Project Kaisei also researched the patch. Researchers were also looking at the impact of plastic on mesopelagic fish, such as lanternfish.