Mackerel may refer to: Mackerel, any of a number of different species of fish Mackerel as food Mackerel sky, a formation of altocumulus clouds Mackerel, a type of Tabby cat Great Mackerel Beach, NSW, Australia Mackerel Islets, two small islands off eastern Tasmania, Australia , the name of three ships of the Royal Navy , the name of two submarines of the U.S. Navy