She replaces Rebecca Gray, who left the charity in December after nine years in position.
Holloway has direct experience of working with the charity and its key partners through her current role across both South London and Maudsley NHS Foundation Trust and the Institute of Psychiatry, Psychology and Neuroscience at King's College London, as programme director for the King's Maudsley Partnership to improve children and young people's mental health.
Frances Corner, chair of trustees at Maudsley Charity, said: ‘Her passion, understanding and experience in the mental health landscape and her commitment to working in partnership with others will help us leverage impact throughout our next strategic period and drive us closer to achieving our mission where everyone with a mental illness, without exception, gets the right care and support for them.'
Maudsley Charity has a more than £40m commitment over five years to improve the mental health landscape across south London with ambitions and plans to amplify and extend the impact of its funding.
She said: 'As the largest specialist funder in mental health, we have a huge opportunity to generate innovation in practice and also to scale what we know works. Both will improve support and address longstanding inequalities for people living with mental illness in South London and beyond.
'We can only have impact through working in partnership, and I am looking forward to extending and developing our relationships, both locally and nationally.'
Holloway will join the charity at the beginning of April ready for the new financial year.