Ms Still has no previous experience of working at board level in football but boasts a dynamic CV which includes working in the fashion industry for Bulgari and Gucci.
It is believed that the University of Durham politics graduate is the youngest in the football industry to hold such a high profile role at a football club.
"It's a great privilege for me to be offered the chance to lead this football club," Ms Still said on the Mansfield official website.
"I intend to add vibrancy and fresh ideas to our approach off the field.
"Having attended numerous fundraising events, organised by the club's supporters groups, I am aware of the passion and enthusiasm that the fans have to see the Stags succeed.
"I want to wake the sleeping fans with a lot of different initiatives by liaising with them and finding what they want.
"Much work has been done to develop relationships with key businesses in and around the area, and we must continue to work hard to ensure that our off-the-field commercial activity increases in an attempt to make the club self-sustainable.
"The club must continue to forge close relationships with the local, community, businesses and supporters and it will be my job to ensure that these are strengthened to maximise both our revenue and our position in the local community.
"We have a fantastic team both on and off the field and I am pleased to accept this role during a time when there appears to be a real buzz around the place."
Ms Still succeeds Steve Barker who has moved to a new position with Chairman John Radford's One Call Group.