Isabella "Isa“ Summers is an English multi-instrumentalist, songwriter, and backing vocalist, currently signed to the record label Island Records. She was a member of the English indie rock band Florence and the Machine from 2007 to 2018, playing various instruments including keyboards, percussion and backing vocals. She has also worked as a session musician and backing vocalist for a number of other artists, including Jack Garratt, Bat for Lashes and Laura Marling.