Baroness Barran has been appointed as the Minister for Civil Society, the Department for Digital, Culture, Media and Sport has confirmed.
The peer, who was previously a government whip in the House of Lords, has taken over from Mims Davies MP, who departed the role at the weekend.
Barran will not combine the role with sport, which was half of Davies' portfolio, but will instead share it with her work representing the DCMS in the House of Lords.
She will also take on DCMS work on youth and social action, loneliness and the Government Inclusive Economy Unit.
Barran has been a Conservative member of the House of Lords since June 2018.
She was previously the chief executive of the domestic abuse charity Safe Lives, which she led between 2004 and 2017.
She was head of grant development at the think tank New Philanthropy Capital from 2001 to 2004, and worked in asset management and for a hedge fund before moving into the charity sector.
Barran said it was an "absolute honour" to take up the role.
"I have been a proud, passionate advocate of civil society for many years and have seen first hand how the hard work of our charities, volunteers, social enterprises and responsible businesses improves lives up and down the country," she said.
"I am delighted to be able to use my experience to listen, champion and enhance the role of civil society in building stronger communities and a fairer society for everyone."
In a statement, Caron Bradshaw, chief executive of the Charity Finance Group, said it was great that a Minister for Civil Society with a long background in the sector had been appointed.
But she expressed concerns that appointing a member of the House of Lords to the post showed the brief was low on the government's list of priorities.
"It’s great to see the appointment of a new minister with a background in civil society, and it’s good that the charities brief is no longer shared with sport," Bradshaw said.
"However, the appointment of a peer to the role, together with the time taken to make an announcement, suggests that we must continue to lobby for a higher priority to be given to civil society in this government."
Sir Stuart Etherington, chief executive of the National Council for Voluntary Organisations, said that Barran's background in charities meant her "commitment and passion for our sector is clear".
Etherington said he hoped the more focused ministerial brief would "provide charities and volunteering the time and government support they need to continue to thrive at the heart of society".
He said: "It is nearly a year since the launch of the Civil Society Strategy, which set out a bold agenda for the future of the social sector. But progress on its ambitions has been modest.
"We look forward to working closely with Baroness Barran to help the government move this vision forward."
Vicky Browning, chief executive of Acevo, the body for charity chief executives, said: "The announcement was regrettably late coming but good news when it arrived.
"It's great to have a minister with such solid civil society experience."
With the government's majority currently at two MPs, Jay Kennedy, director of policy and research at the Directory of Social Change, said: "It’s encouraging to see they’ve appointed someone who seems to have real hands-on experience and knowledge of the charity sector.
"But with all the political turmoil going on right now, how long will she last?"
Sir John Low, chief executive of the Charities Aid Foundation, welcomed the appointment as an opportunity to bridge divides in the country. But he said that the profile of the sector needed to be raised across government.
"With the first anniversary of the Civil Society Strategy coming up next month, there is an ideal opportunity to revitalise this work," he said. "A great starting point is to ask DCMS to stress to colleagues across government the need to place charities at the forefront of their thinking.
"As always we stand ready to support the minister in raising the profile of civil society across the UK."
The new government has said it is prepared to enact a no-deal Brexit at the end of October, and Keiran Goddard, director of external affairs at the Association of Charitable Foundations, said that the prospect was having a serious impact on charities.
"We call on the minister to act swiftly to resolve the ongoing uncertainty about the Shared Prosperity Fund, to speed up the release of dormant assets that can be used to support communities and to fulfil the government’s stated vision of the UK as a global centre for philanthropic practice," Goddard said.
"Charities are facing enormous challenges; rising need and the prospect of a no-deal Brexit are putting pressure on already stretched resources. It is crucial that the new minister takes urgent action to support charities in meeting these challenges."