[3] She was educated at James Allen's Girls' School in Dulwich, and joined Youth Music Theatre UK and its production of Red Hunter in 2005.
[5] In 2004, Ritchie played a lead role in a short film entitled The Open Doors with Michael Sheen.
She stars alongside Tom Stourton in the BBC Three sitcom Siblings, which was first broadcast in summer 2014, and she appeared as a guest panellist in the same year on 8 Out of 10 Cats.
In 2015, Ritchie joined the cast of the popular period drama Call the Midwife, playing Nurse Barbara Gilbert (Hereward) until March 2018.
From 2019 to 2023, she played Alison alongside Kiell Smith-Bynoe as Mike in Ghosts, a BBC sitcom about a young couple who inherit a haunted estate.