The 55-year-old from Watermead aims to complete a 1,500m swim, a 40km bike ride and a 10km run every day for over three months, including Christmas Day.
He said: "I will attempt to complete 100 Olympic-distance triathlons in 100 days, almost all will be done from Nuffield Health gym in Fairford Leys, Aylesbury.
"This will be 100 consecutive days, including Christmas Day and New Year’s Day."
The epic challenge is launched next Wednesday, 31st October at the Association of Police and Crime Commissioners and National Police Chiefs’ Council Conference at the Queen Elizabeth II Centre in Westminster.
Commenting on the biggest challenge of his life, Mr Lander, who is the Editor of the weekly journal Police Professional, said: “The UK Police Memorial is very dear to my heart. In 1984 when I was a serving police officer with West Yorkshire Police, one of my colleagues Sergeant John Speed was shot and killed outside Leeds Minster, whilst on duty, when he went to the aid of a colleague.
“His death had a profound impact on the whole city, and brought home how, every day, officers without hesitation step into danger to protect the rest of us.
“John was murdered on 31st October and I thought that it would be a fitting and personal tribute to him and his family to start my challenge on that day.”
The 100 Day challenge will see Mr Lander swim almost 100 miles, cycle for 2,500 miles and run for over 600 miles, mostly in and around Buckinghamshire and Oxfordshire.
He has previously taken part in more than 30 triathlons over the last decade, and represented Great Britain in his age group at the 2014 Triathlon World Championships in Canada.
Mr Lander added: “This will be the most difficult challenge I have ever done but as I begin each triathlon I will read the names of the officers who died on duty on that day. By completing each one I will honour their sacrifice but also give gratitude to every officer who is out there now protecting the rest of us.”
The Police Memorial Trust has so far raised over £3.5 million of a required £4.5 million to build a fitting tribute to the ultimate sacrifice made by over 4,000 police officers.
"A physical structure at the National Memorial Arboretum in Staffordshire will offer relatives, friends and colleagues a place to peacefully reflect and remember officers who died on duty. A digital memorial will allow anyone in the world to access details of officers killed and a Living Memorial will maintain the memorial forever and support relatives as and when needed.
Sir Hugh Orde, Chair of the UK Police Memorial Trust said: “This is an amazing challenge that Paul has set himself. The Trustees and I are extremely grateful to him for raising funds and awareness of the UK Police Memorial and we wish him every success. We hope that the public will get behind him and support him on his epic journey.”