The question of the “biggest fish in the world ever caught” is complicated because “biggest” can be defined by length, weight, or the specific rules under which it was caught, such as on a rod and reel by a sport fisherman. The record holder changes depending on whether the search is for the heaviest fish species in the ocean, the largest fish that lives exclusively in freshwater, or the single heaviest catch recorded by an accredited fishing association. Separating these categories is necessary to identify the true giants of both the open ocean and inland waters.
The All-Time Heaviest Catch Record
The heaviest fish ever recorded and accepted under international sport fishing organizations is the Great White Shark. The overall record belongs to a Great White Shark caught off the coast of Ceduna, South Australia, in 1959 by angler Alfred Dean. This specimen weighed 2,664 pounds (1,208 kilograms), a record that has stood for decades and remains the benchmark for the largest fish landed by a single angler using a rod and reel.
To qualify for this record, the catch must adhere to International Game Fish Association (IGFA) All-Tackle rules, which require the fish to be fought and landed by one person using specific gear types. While other large marine game fish like the Black Marlin and Bluefin Tuna also hold impressive records—such as a 1,560-pound Black Marlin caught in 1953 and a 1,496-pound Atlantic Bluefin Tuna caught in 1979—the Great White Shark remains significantly heavier. The record is likely to remain unbroken, as Great White Sharks are now a protected species globally, making fishing for them illegal and record validation impossible.
The Largest Freshwater Records
The biggest catches documented in rivers and lakes are tracked separately from marine species. Historically, the largest freshwater fish ever recorded was a Beluga Sturgeon, an anadromous species that migrates to freshwater to spawn. One specimen, caught in the Volga River in 1827, weighed 3,463 pounds (1,571 kilograms) and measured over 23 feet long. While modern Beluga Sturgeon rarely exceed 500 pounds due to overfishing, this historical catch demonstrates the size freshwater species can attain.
Another contender is the Mekong Giant Catfish, which can exceed 600 pounds and grow over 10 feet in length, making it the largest fish in Southeast Asia’s Mekong River. A more recent record for a purely freshwater fish caught on rod and reel is a White Sturgeon, which weighed 468 pounds and was caught in the Fraser River, Canada, in 1983. The Giant Freshwater Stingray is also a large species, with a specimen caught in Cambodia weighing 661 pounds, a weight that recently surpassed the largest verified Mekong Giant Catfish.
The True Giants: The World’s Largest Fish Species
When considering the largest fish species without the constraint of being “caught” under sport fishing rules, the title belongs to the Whale Shark (Rhincodon typus). Individuals commonly reach lengths of up to 60 feet (18.3 meters) and weigh up to 20 tons (18.1 metric tonnes). They are filter feeders, consuming plankton and small organisms, and pose no threat to humans.
The second-largest fish is the Basking Shark (Cetorhinus maximus), which can grow up to 40 feet in length, also feeding as a filter feeder. These two species are the largest extant fish, far exceeding the size of any game fish caught on a rod and reel. These giants are typically excluded from “biggest ever caught” lists because they are protected, are not considered game fish, and are too large to be landed by conventional angling methods.