Ethel Mary Bassett Haythornthwaite (née Ward) MBE (18 January 1894 – 11 April 1986) was an English environmental campaigner, activist and poet.

In 1937, she married Gerald Haythornthwaite, a lieutenant colonel in the army who served overseas in Norway during World War II.

[6][7] She soon became enamoured of the rural beauty surrounding the city of Sheffield, and decided to apply herself to protecting the countryside from development and urban sprawl.

"[10]Haythornthwaite spent most of 1942 in London, "leading the national organisation in the crucial early debates on how the post-war reconstruction of the country should be achieved by democratic planning".

We shall not see the likes of Ethel and Gerald again.” In 1994, eight years after Haythornthwaite died, a woodland was planted near Dore in honour of the charity founders.

[17] The route consists of twenty stages that broadly follows the park's boundary, as envisaged by Haythornthwaite and her husband,[18] covering a total distance of 190 miles.

[21] Councillor Sioned-Mair Richards, cabinet member for neighbourhoods at Sheffield Council said: “The maintenance of privately bought memorials is always the responsibility of the family or purchaser.

The graves of Sir Stuart Goodwin and Lt Col Gerald Haythornthwaite are private memorials and therefore their families are responsible for maintaining them.

“We acknowledge the significant contributions they made to the city and those of the many others buried in our cemeteries who gave generously, fought bravely and were champions for Sheffield.

“And whilst we would like to be able to maintain all neglected memorials, we have never funded private graves because budget pressures make it impossible for us.

“We have no objections to repairs being carried out and should the family or purchaser wish to instruct a stone mason we can provide information to help them do this.”Following a public appeal in 2018, the graves of Haythornthwaite and her husband as well as her father and mother were restored.

The episode marked the 70th anniversary of the national parks of the United Kingdom and covered the impact of her legacy in Sheffield and the Peak District.

[25] Smart also mentions how it was Ethel Haythornthwaite's vision for the soldiers post-war to come home to their Jerusalem, a reference to the poem by one of her favourite poets, William Blake.

[3] On 19 April 2021, during a trespass debate, Olivia Blake MP for Sheffield Hallam referenced Haythornthwaite as she opposed the Government's proposal to impose harsher measures.

On 25 May 2022, a blue plaque to commemorate the life of one of Sheffield and the Peak District’s leading environmentalists and most influential women was put in place.

In August 2021, Tomo Thompson, CEO of CPRE PDSY and a former mayor of Sheffield, stated that there was a plaque in honour of Haythornthwaite at Longshaw and a small tribute located at Dore.

[38] On 8 March 2024, to celebrate International Women's Day and 100 years of CPRE PDSY, the National Trust hosted a talk on the life and work of Haythornthwaite followed by a guided walk up Higger Tor, the closest Ethel to Longshaw Estate.