Fungi can be used to flocculate and harvest microalgae at a high efficiency in a more resource- and cost-efficient, and sustainable manner than traditional microalgal harvesting methods. However, the two most common fungal-assisted microalgal harvesting methods are lengthy. Here, we describe a more rapid fungal-assisted microalgal harvesting method using Pleurotus ostreatus or Penicillium corylophilum mycelia in suspension as bioflocculants. The fungal mycelia can be cultivated in any suitable growth medium, and the technique is applicable across microalgal species.