It usually schools over sand or mud bottoms, feeding on zooplankton, dead plant matter, microalgae and detritus.

[5] The flathead mullet is cosmopolitan in coastal waters of the tropical, subtropical and temperate zones of all seas,[2] as far north as the Bay of Biscay and Nova Scotia in the Atlantic Ocean.

They are able to live in a wide range of salinity and so may also be found in lagoons, lakes and far into estuaries, but migrate back to the sea to spawn.

[7] In the Colorado River mullet are pelagic in larger pools, sometimes moving into currents below dams, and generally occurring in small groups.

[5] The mullet populations are currently declining in Arizona, due to periods when the Colorado River does not reach the Gulf of California.

[9] The previously understudied osteological development of Mugil cephalus was investigated in a 2021 study, with four embryonic and six larval developmental steps being described in aquaculture-reared and wild-caught specimens.

[9] The roe of this mullet is salted, dried, and compressed to make a specialty food across the world, such as Greek avgotaraho, Taiwanese Wuyutsu, Korean eoran, Japanese karasumi, Italian bottarga, French poutargue, Turkish Haviar and Egyptian batarekh.