Nighy was born in London, the daughter of actors Bill Nighy and Diana Quick. She was educated at the City of London School for Girls and Westminster School. Nighy graduated with First-Class Honours in English from University College London in 2006. She is a former member of the National Youth Theatre.
Nighy is a Director of Foster Films. She has directed short films including Lulu and Player, the latter was written by Sam Hodges, and premiered at the 2008 Miami Short Film Festival. She directed Hodges' play Lyre at the HighTide Festival in spring 2007.
