The 10K Cookridge Community Run and a 2k fun run will be held in north Leeds on Sunday May 19 in memory of Gareth Dunn of Cookridge.
Mr Dunn's friend David Smart is helping organise the runs along with Abbey Runners.
Mr Dunn was suffering from terminal cancer when he completed the London Marathon with a prosthetic running blade in May 2018.
The marathon was one of the fundraising challenges Mr Dunn was determined to conquer to raise £100,000 for Cancer Research UK, and in particular research into synovial sarcoma.
He achieved his fundraising goal before tragically losing his fight for life last October.
Mr Dunn's Just Giving Page at www.justgiving.com/fundraising/chemotionally-unstable has so far registered more than £115,000 raised.
Mr Dunn set up online blog Chemotionally Unstable when he was given his terminal diagnosis.
In his blog posts, Mr Dunn discussed all aspects of living with incurable cancer from treatment and mental well-being to fitness.
And Mr Dunn told his story in his own words in a 2017 video filmed by Cancer Research.
Mr Smart, 36, of Cookridge, said: "He was an amazing, inspirational person whose efforts were just infectious.
"We just wanted to continue his legacy and his fundraising in his name."
Mr Dunn was about to start the demanding army officer training course at Sandhurst when he was diagnosed with cancer in his foot and had to have his right leg amputated below the knee.
Mr Dunn told the YEP in November 2017: "The timing was incredibly cruel. I had worked hard to get my place at Sandhurst and had planned my life as an army officer in the Paras, but just as I was about to realise my dream, suddenly it was snatched away from me.”
Despite the massive blow, talented sportsman Mr Dunn was determined to fight back and focused on joining the GB Paralympic squad.
He was back in the gym two weeks after his operation and three months after surgery, he was fitted with a prosthetic running blade.
He went on to successfully apply to train with the cycling, canoeing and athletics squad of the GB Paralympic team.
He also embarked upon a new career challenge in international affairs with the aim of joining the Foreign and Commonwealth Office.
But just as it seemed he had his life back on track he was dealt the most cruel of blows.
A scan showed a massive tumour in his left lung and 14 smaller ones in his right lung.
After Mr Dunn was diagnosed with terminal cancer, he set himself a series of fundraising challenges and achieved his target of raising £100,000.
The 10K Cookridge Community Run and 2k fun run will benefit two charities - Cancer Research and OPAL (Older People’s Action in the Locality).
The races are sponsored by house builder Taylor Wimpey, golf club Cookridge Hall and other local businesses.
Cookridge Scouts Group and running club Abbey Runners are supporting the races.
Details of the races and how to enter can be found at www.cookridgecommunityrun.co.uk