Shopkeeper Alice Wheeldon was found guilty of a poison plot against David Lloyd George in 1917.
Since her death in 1919, a campaign has emerged to clear her name.
Her former home at 12 Pear Tree Road, Normanton, is being marked with a plaque in a ceremony organised by Derby Civic Society and the city council.
Keith Venables, from the Derby People's History group, which campaigned for justice for the family, said: "It's wonderful to celebrate the contribution of Alice Wheeldon and her family. Their name was vilified."
Mrs Wheeldon, a mother of four, supported the suffragette movement and was a conscientious objector to World War I.
Mr Venables believes she was framed by the authorities who were anxious about opposition to the war.
The radical women who fought for the vote
The family claimed an MI5 agent, posing as an objector, embroiled Mrs Wheeldon in a plot to poison dogs guarding prisoners against the war.
However, the family were accused of plotting to murder the prime minister by shooting him with poisoned darts.
On 31 January 1917, Mrs Wheeldon, her daughters Hetty and Winnie and son-in-law Alfred Mason were arrested and charged.
Mrs Wheeldon was sentenced to 10 years, Alfred seven years and Winnie five years. Hetty was acquitted.
Mrs Wheeldon went on a hunger strike and was released after nine months but died shortly afterwards.
Historian Dr Nicholas Hiley, who researched the family's story, said: "The whole thing was a travesty.
"The truth about Alice Wheeldon deserves to be publicised and the blue plaque is the beginning of that. The Wheeldons should be honoured and remembered for the stand they took during the war."
Mrs Wheeldon's descendents moved to Australia, but her great-granddaughters, Deirdre and Chloe Mason, are visiting Derby for the ceremony.
They hope to prepare a miscarriage of justice application to go before the Criminal Cases Review Commission.

She was a passenger in a car that collided with a lorry on the Legacorry Road at about 15:35 GMT on Thursday.
The woman who was driving the vehicle is in a critical condition in hospital.
In a separate incident, Moor Road in Coalisland, County Tyrone, has been closed following a two-vehicle crash.

13 September 2016 Last updated at 09:29 BST
Emily, who is 11, submitted her short story called The Last Sign to the Jacqueline Wilson Creative Writing Prize, with the author herself picking the winner.
The story reads like it's about an older lady reminiscing about her past before she dies, but the twist at the end is that she is actually a chimpanzee.
The Last Sign will now feature in Jacqueline's new book, which is called Clover Moon.
Jacqueline said: "It was very tough to select just one winner but Emily's story stood out because of its use of language and originality".
Newsround brought Emily and Jacqueline Wilson into the Newsround studio, where they met for the first time and talked about Emily's story.
The competition was open to 7-12 year olds, and they could write about anything they liked, between 750 and 1000 words.

More than 700 students will be taught at the new state-of-the-art Deeside Sixth building.
The £14.6m college is part of a major overhaul of post-16 education by Flintshire council.
First Minister Carwyn Jones will open the facility, based at Coleg Cambria's Deeside campus, on Friday.
In 2013, it was announced that sixth forms at Holywell, John Summers and Connah's Quay high schools were to be axed, with students instead moving to the new college.
A Derby suffragette, who was convicted of attempting to murder a prime minister, is being honoured with a blue plaque.
[NEXT_CONCEPT]
A 20-year-old woman has died in a crash in Richhill, County Armagh.
[NEXT_CONCEPT]
A schoolgirl has beaten thousands of children to get her short story written in Jacqueline Wilson's new book.
[NEXT_CONCEPT]
A multi-million pound sixth form college centralising post-16 education in Flintshire has officially opened its doors.