YouTubers from Hertfordshire

Olajide Olayinka Williams "JJ" Olatunji ( born 19 June 1993), known professionally as KSI, is a British influencer, musician, and former professional boxer. He is a co-founding member of YouTube group the Sidemen, the co-founder of Misfits Boxing and co-owner of several businesses, including Prime Hydration and Lunchly. KSI has also served as a judge on ''Britain's Got Talent'' since 2026.

Mark Ian Hoyle (born 12 April 1987), known professionally as LadBaby, is an English YouTuber, musician, and blogger. His content focuses on his experiences as a father and is usually filmed in collaboration with his wife, Roxanne. The couple garnered the Christmas Number One on the UK Singles Chart for five years from 2018 to 2022, the most consecutive and overall for any artist, with the sausage roll-themed novelty songs "We Built This City", "I Love Sausage Rolls", "Don't Stop Me Eatin'", "Sausage Rolls for Everyone" and "Food Aid". This made them the first musical act in British history to