The 41-year-old, mother of two was attacked shortly after a constituency surgery that she held in Birstall, West Yorkshire on Thursday 16th June.
Her attacker shouted “put Britain first” at least two times, according to an eye-witness testimony. A 52-year-old man, named Tommy Mair, has been arrested.
Hillary Clinton, the US Democratic Party’s presidential hopeful was among those who honoured Mrs Cox, she said: “It is cruel and terrible that her life was cut short.”
She adds: “It is critical Britain and the United States stand together against hatred and violence.”
The death of Jo has hit many people with a deep sadness, most of all her husband and children who have been affected the most.
Mrs Cox’s husband gave a heartfelt statement, saying:
“Today is the beginning of a new chapter in our lives. More difficult, more painful, less joyful, less full of love.
“I and Jo’s friends and family are going to work every moment of our lives to love and nurture our kids and to fight against the hate that killed Jo.
“Jo believed in a better world and she fought for it every day of her life with an energy, and a zest for life that would exhaust most people.
She would have wanted two things above all else to happen now, one that our precious children are bathed in love and two, that we all unite to fight against the hatred that killed her.”
Tributes have also been paid from across Europe to Mrs Cox, who was campaigning for Vote Remain.
Rachel Reeves, Labour MP for Leeds West, said: “Jo was so loved in her community she was part of it and MPs, if they are going to do their job, need to be part of their community to do these advice surgeries.
“We can’t let the behaviour of one man destroy that link between MPs and their constituencies.”
Hundreds of people of all faiths gathered together on Thursday in Saint Peter’s Church in Birstall for a service of remembrance while a vigil also took place outside Parliament.
Churches in the area of Batley have proclaimed that they will be open on Friday for those who want to pay their respects.
The Rt Rev Dr Jonathan Gibbs, The Bishop of Huddersfield, said: “All of us held Jo in enormous affection and respect. The sadness is seeping into us more deeply.”
“I was privileged to know Jo, it’s going to be a really tough day we’ll be drawing deep on the resources of our faith.”
Prime Minister David Cameron was also among those to speak of Jo, he said: “The death of Jo Cox is a tragedy. She was a committed and caring MP.”