Rehman Chishti is to take over from Lord Tariq Ahmad of Wimbledon as the new Prime Minister's Envoy for Freedom of Religion & Belief.
Mr Chishti, a Muslim, was previously the Vice Chairman of the Conservative party covering faith and communities, and was an outspoken critic of the Government's handling of persecuted Christian woman Asia Bibi's appeal for asylum.
Responding to his appointment, Mr Chishti said: "I am delighted to have been appointed as the PM's Special Envoy. I have championed freedom of religion and beliefs for much of my life.
"I shall use the UK Government's global network to take real action to support those persecuted for their faith or belief, and promote greater understanding and respect between faiths.
"As someone whose family came to the UK when I was six years old, and my father had taken up a role as an Imam, my family and I have always been able to openly and freely practise our faith.
"I want to ensure every citizen around the world is able to enjoy this basic right. Freedom of Religion, practice and belief is one of the foundations of a free society.
"I pay tribute to Lord Ahmad for all his work on this area over recent years."
The role of Special Envoy for Freedom of Religion & Belief was created by former Prime Minister Theresa May to further the Government's advocacy for the rights of people around the world being persecuted or discriminated against for their beliefs.
Mr Chishti will have the responsibility of implementing the findings of a major review into persecution that was commissioned by former Foreign Secretary Jeremy Hunt.
The review was overseen by the Bishop of Truro, Philip Mounstephen, and revealed the staggering scale of persecution against Christians worldwide, while also examining injustices suffered by people of other minority faiths like the Rohingya in Myanmar and Yazidis persecuted by the Islamic State.
The final report made several recommendations, including the imposition of sanctions on the worst offenders of persecution. It also asked that the UK take the lead in securing a new Security Council Resolution calling on all governments in the Middle East and North Africa to protect Christians.
Following the release of the report in July, the Government pledged to accept all of the recommendations.
The Government said Mr Chishti would "bring together efforts across the UK Government, with faith actors and civil society to promote the UK's firm stance on religious tolerance abroad".
Prime Minister Boris Johnson said: "People across the world deserve the chance to practise their beliefs freely. I'm delighted to appoint Rehman as my new Special Envoy and look forward to him building on the important work we have already done on this issue.
"The UK will always be a passionate advocate for greater tolerance, respect and understanding internationally."
Foreign Secretary, Dominic Raab, said: "A staggering 83% of the world's population live in nations where religious freedom is threatened or banned. It is an area where the UK can and must make a difference. I'm delighted to be working with Rehman to enhance the UK's support for those suffering persecution based on their faith, and standing up for this essential freedom."
Mr Chishti's appointment was welcomed by former Bishop Michael Nazir-Ali, head of the Oxford Centre for Training, Research, Advocacy and Dialogue, who came to the UK after experiencing persecution in his native Pakistan.
He said: "I warmly welcome the appointment of Rehman Chishti MP as Prime Minister's Envoy for Freedom of Religion and Belief. His appointment will focus the Government's policy on this most important issue in our world today.
"There are important challenges ahead in freedom of speech, thought and living according to our beliefs as set out in Article 18. I expect Ambassador Chishti to be vigorous in addressing these challenges."
Mervyn Thomas, Chief Executive of Christian Solidarity Worldwide, said: "CSW congratulates Rehman Chishti MP on his appointment. He has always been outspoken on issues relating to freedom of religion or belief and we look forward to working with him as he takes on this new role.
"We also wish to express our sincere gratitude to Lord Ahmad of Wimbledon for all he has done during his tenure for religious communities around the world whose rights have been violated, and to thank him for his commitment to continue to champion FoRB and other human rights as Minister of State."