She and Valegro scored 87.46%, capping her previous record of 87.129%, set at the FEI World Cup Final in Lyon in April.
The pair scored 17 10s in their fault-free performance.
“He hadn’t been out since the World Equestrian Games [in August],” said Charlotte of the 12-year-old gelding by Negro. “So I kind of used this as a schooling round.”
The 29-year-old rider has had a whirlwind week, having come fourth in the BBC Sports Personality Of The Year contest on Sunday evening in Glasgow.
“There is nothing scarier than getting up on stage in front of 12,000 people and being interviewed,” she said. “So coming to Olympia was a complete breeze.”
When asked if she had been gunning to break the record this evening, she said: “Win or lose, if Blueberry [Valegro] has tried his hardest and I’ve done my best, the score is irrelevant; the record is a bonus.”
The two Netherlands combinations of Edward Gal (Glock’s Undercover) and Danielle Heijkoop (Siro) were second and third, replicating the placings exactly in the grand prix and freestyle at Olympia in 2013.
Edward, who followed Chralotte into the arena and scored 80.12%, said: “Undercover got hot with all the clapping for Charlotte. That was hard and I had to hold him back in the test. But this is a great show and it’s really nice to come here at Christmas time.”
Danielle echoed Edward’s sentiments: “I love London – I love the shopping and the people, oh and the dressage.”
Carl Hester was fourth on an incredibly sensitive Nip Tuck, scoring 74.68%.
The top 15 all qualify for the freestyle on Wednesday.
Nikki Crisp and Pasoa were 14th with 68.22%. Fellow Brits Hannah Biggs (63.46% on Weltzin) and Daniel Watson (63.44% on Fideramber) had to contend with tense horses in the electric atmosphere and filled 17th and 18th places.