The 26-year-old native of Split swam across the Strait of Gibraltar in three hours and three minutes in fairly challenging sea conditions, her crew said.
Levačić has thus swum the fifth of the Oceans Seven, a marathon swimming challenge consisting of seven open water channel swims.
She still has to conquer the North Channel between north-eastern Northern Ireland and south-western Scotland, and the Cook Strait between the North and South Islands of New Zealand.
Levačić is the first woman from Croatia to have swum the English Channel, and she is the sixth person and second woman in the history of long-distance swimming to have swum, in 90 days, the Manhattan Island marathon, the Catalina Channel (between Santa Catalina Island and Southern California) and the English Channel.