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Dujardin, 30, set world records in winning the freestyle dressage and grand prix events last year.
The double Olympic and world champion will ride Uthopia instead of her usual horse Valegro in Wednesday's freestyle.
Brash, the first rider to complete the sport's grand slam, competes in the World Cup showjumping on 20 December.
Four members of the Whitaker family, John, Michael, Robert and William, are also set to compete during the week, while Ben Maher, another London 2012 gold medallist, seeks to defend his Grand Prix title on Monday, 21 December.
Wednesday 16 December
Live coverage of the World Cup dressage freestyle
Red Button, online & connected TV from 20:00 to 22:35 GMT
Thursday 17 December
Live coverage of the Olympia Puissance high-jump competition
Red Button, online & connected TV from 21:00 to 22:15 GMT
Sunday 20 December
Live coverage of the latest World Cup leg, plus highlights of the puissance high-jump competition
BBC Two, online & connected TV from 13:45 to 16:30 GMT
Monday 21 December
Live coverage including the Olympia Grand Prix
Red Button, online & connected TV from 18:45 to 22:25 GMT
Wednesday 23 December
Highlights of the week, including the Olympia Grand Prix
BBC Two HD, online & connected TV from 11:00 to 12:00 GMT
All programmes times subject to change

Bevan, 18, who won team silver at the World Championships in Glasgow last month, has had surgery.
He broke his left tibia and fibia after landing on a concrete floor in what he described as a "freak accident".
He wrote on Instagram that the injury was heartbreaking and the "lowest low" after "such a high of the Worlds".
British Gymnastics' medical team is expected to issue more information on the teenager's injury on Tuesday.
It is yet unclear whether the Essex-based gymnast has a chance of returning to fitness to secure one of three individual spots available on the British team, as well as a place in the team event, at next summer's Olympics in Rio de Janeiro.
"All my emotions just erupted and I've found myself constantly in tears," Bevan said.
"This may be a big stepping stone to overcome but most, if not all, successful athletes have had to overcome adversity to reach their goals.
"That moment at the World Championships I will never forget and it's something I want to feel again."

Liverpool-bound striker Dominic Solanke picked up Lewis Cook's pass to score the winner shortly after the interval.
England played the last 17 minutes with 10 men after Josh Onomah was sent off.
Freddie Woodman was required to make key saves late on as Paul Simpson's side held on to reach the semi-finals for the first time in 24 years.
Italy beat Zambia 3-2 after extra time and will face England in Jeonju on Thursday.
The other semi-final sees Uruguay take on Venezuela.
After a goalless first half, Bournemouth midfielder Cook split the Mexico defence with an exquisite ball from deep that Solanke, who will join Liverpool from Chelsea next month, ran on to before firing past Abraham Romero.
England also saw a goal-bound deflection cleared off the line and Onomah hit the post before the Tottenham midfielder was dismissed in contentious circumstances.
The 20-year-old appeared to make accidental contact with Juan Aguayo as he ran past his marker but was shown a second yellow card that rules him out of the Italy game.
England Under-20s last reached the final four of this competition in 1993, when a squad featuring Nicky Butt and Nick Barmby lost to Ghana in the semis before beating Australia to finish in third place.
BBC sports editor Dan Roan
These are encouraging times for English youth football. Last season, the Under-21s won the Toulon tournament for the first time in 22 years. Last month the Under-17s reached the final of the European Championships.
The U20s have now done something no England team has managed since 1993.
In fact, England failed to qualify for five of the last 11 Under-20 World Cups, and did not win a game in the other six.
The FA believes this current success is testament to the continuity and technical support representative teams receive at the National Football Centre at St George's Park, and improved trust with clubs over the release of young players.
But with the top clubs awash with TV money and increasingly able to buy proven foreign talent, the concern will be that the path to first-team football for home-grown youngsters is harder than ever.
Olympic champions and world number ones Charlotte Dujardin and Scott Brash head the field at the London International Horse Show at Olympia on Tuesday.
[NEXT_CONCEPT]
British gymnast Brinn Bevan suffered a double leg break while vaulting on Saturday, putting in doubt his hopes of competing at next year's Olympics.
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England will face Italy in the semi-finals of the Under-20 World Cup in South Korea after a 1-0 victory over Mexico in Cheonan.