Allsopp is the eldest child and daughter of Charles Allsopp, 6th Baron Hindlip, a former chairman of Christie's, by his marriage to Fiona Victoria Jean Atherley McGowan (1947–2014).[4][5] She has a younger brother, Henry William (b. 1973), and two younger sisters, Sofie (b. 1980) and Natasha Fiona (b. 1986).[6] Owing to her father's peerage, she is entitled to use the courtesy style The Honourable Kirstie Allsopp.[7] The designer and businesswoman Cath Kidston is her cousin.[8][9]
She attended ten schools as a child,[10][11] including St Clotilde's in Lechlade, Gloucestershire,[12] and Bedales near Petersfield, Hampshire. After spending time in India teaching English, Allsopp returned to the UK and began a series of positions, working for Country Living and Food & Home magazines and her mother's business, Hindlip & Prentice Interiors, and studying at Christie's.[citation needed] Allsopp set up her own home search company, Kirmir, in 1996, focusing on top end purchases in Central and West London.[13]
Her partner is property developer Ben Andersen, and they have two sons, Bay (b. 2006) and Oscar (b. 2008).[15] She is also stepmother to her partner's two sons from a previous relationship. They live in London.[16]
In 2009 Allsopp and her family bought and restored a house called Meadowgate, in rural Devon. It had been empty for 39 years. The restoration and interior decorating were the subject of the TV series Kirstie's Homemade Home.[17] It was again the setting for her Kirstie's Homemade Christmas programme, showing people how to have an individual Christmas using secondhand and homemade products such as wreaths from material found from nearby woods.[18]
Allsopp was criticised in 2022 for comments she made about people not being able to purchase housing, arguing many people are not willing to make enough sacrifices like cutting out coffee, Netflix and going to the gym. Allsopp, who received financial support from her family to purchase her first home, claimed "...there are loads of people who can [make sacrifices] and don’t." Following criticism Allsopp posted several responses on Twitter before quitting the platform.[19]
