Jellyfish blooms are a conspicuous feature of our oceans. Negative interactions between jellyfish and humans are widely publicised, such as jellyfish disrupting power supplies by clogging cooling water intakes of power plants or interfering with commercial fishing operations. Yet jellyfish have delivered many benefits to humans, such as being the original source of a unique molecule, the “green fluorescent protein”, that has revolutionised biomedical research. Here we discuss the public and scientific perceptions of jellyfish blooms and emphasise the need for striking a balance in the way jellyfish blooms are portrayed.