Aoshima (Japanese: 青島, Hepburn: Aoshima), also known as Cat Island (Japanese: 猫の島, Hepburn: Neko no shima), is an island in Ehime Prefecture, Japan, known for its large number of feline residents and small number of people. Felines have been reported by news outlets to outnumber humans by ratios between 6:1 and 10:1, but as elderly inhabitants of the island have died, the ratio has greatly increased, to almost 36:1. Cats were introduced to combat rodents on fishing boats but remained on the island and reproduced in large numbers.

The feline inhabitants of Aoshima are fed by food donations from all over Japan. They also eat small animals on the island and food from visitors.

The island is roughly 1.6 kilometres (1 mi) long. It was formerly part of Nagahama in Kita District, but as of 2005, it is part of Ōzu city.

The human population on the island has decreased since sardine fisheries became depleted and jobs moved to cities. As of February 2019, only six people live on Aoshima.

In 1945, the island was a fishing village with a population of approximately 900. In 2013, the island was estimated to be home to 50 residents. In 2018, Ehime Shimbun reported that the population had decreased to 13 with an average age of "over 75". In 2019, The Asahi Shimbun Globe reported that only six residents remained on the island. The island attracts tourists who visit the cats and give them food.

The feline population of the island has been reported as between 120 and 130 between 2015 and 2018.

In February 2018, it was reported by Ehime Shimbun that all cats on the island would be spayed or neutered in order to lower the feline population as a response to the declining human population. By October, 210 cats had been spayed and neutered, with another estimated 10 cats uncaptured that had been hidden by an old resident who opposed the program.

The New York Times reported on May 10, 2023, that the island's human population has dropped to five.

Aoshima is accessible via a ferry departing from in front of JR Iyo-Nagahama Station in Port Nagahama, which takes around 30 minutes.

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  Cats scooping food from the islanders at the port.
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  Designated cat feeding area a few minutes from the port. The back is Aoshima Shrine.
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  Cats eating food given at the designated cat feeding area.

• Ainoshima (Shingū), also known as "Cat Heaven Island"
• Tashirojima, also known as "Cat Island"
• Ōkunoshima, known as "Rabbit Island"