[1][3] When her father got the job of professional at Wentworth Golf Club, they moved south to Virginia Water, England, when she was 18 months old.

Gallacher and her younger brother and sister were raised on the Wentworth Estate, where their close neighbours included Bruce Forsyth.

[8] From 2000 until 2004, Gallacher hosted the Sky One show Kirsty's Home Videos, a satellite equivalent of ITV's You've Been Framed!

[8] In December 2005, she released a DVD entitled Body Sculpt with Kirsty Gallacher in which she shows a variety of workouts.

[17][18] On 29 March 2021, it was announced that Gallacher would be joining GB News to present a breakfast programme on the channel.

[21] In January 2024 Kirsty appeared on a celebrity edition of Beat the Chasers but was eliminated early after answering her first question incorrectly.

On Monday 6th January 2025, Gallacher started presenting the drivetime show between 4pm and 7pm on weekdays (4pm and 6pm on Fridays) on Gold Radio.

[29] In April 2023, Gallacher completed the London Marathon in 5 hours, 35 minutes and 35 seconds; she last ran the race in 2019.