Muhammad Salim Khan belongs to Mohmand district in Khyber Pakhtunkhwa. He holds Masters in Political Science from the University of Peshawar. He joined the Pakistan Administrative Service in 1990 and retired as Chief Secretary, Khyber Pakhtunkhwa in 2019.

After completion of his training, he worked as Assistant Commissioner and Sub- Divisional Magistrate in Mianwali, Chiniot, Malsi and Daska in Punjab and Kohat in Khyber Pakhtunkhwa. During 1998-2000, he managed Dir Area Development Project. In 2000-02, he was assigned the charge of Bajaur and Kurram Agencies as Political Agent. These responsibilities were followed by his posting as Project Director to manage the most challenging project in most difficult conditions- South FATA Development Project for Kurram, North Waziristan and South Waziristan. His association with the development of tribal area continued with his placement as General Manager (Planning and Development) in FATA Development Authority. He continued in this role for three years (2007-10) and contributed to the promotion of key economic sectors for boosting development in the tribal region.  In 2012, he was posted to the Embassy of Pakistan in Beijing, China where he remained on diplomatic assignment for four years. During 2010-12 and 2018-19, he looked after different Administrative Departments including Planning and Development, Higher Education, Irrigation, Energy and Power and Science, Technology and Information Technology (ST&IT) Departments. These assignments were caped with his elevation and posting as Chief Secretary, Khyber Pakhtunkhwa in February, 2019.

As Team Leader for implementation of the International Fund for Agriculture Development (IFAD) financed multi sectoral, poverty alleviation and area development projects in Dir (1998-2000) and South Waziristan, North Waziristan and Kurram (2002-05), he was able to tailor the project interventions to address the issue of extreme poverty by harnessing local resources and gender mainstreaming in the conservative areas on the north-western border of Pakistan. He put in place teams of professionals and designed participatory strategies to work in difficult terrain and conservative communities. He steered the constitution of more than 1000 small hamlet-based community organizations (both male and female), trained them to receive project assistance to build rural infrastructure, generate income through agriculture interventions and start small businesses.

In 2017-18, he was on deputation as Registrar Peshawar High Court and led the executive branch of the High Court. A comprehensive Judicial Reforms Strategy, prepared with financial and technical support of the UNDP, was the highlight of this assignment. Use of technology, improving internal accountability, expeditious case disposal, setting up citizen response mechanism, providing friendly environment to visitors and rapid services delivery to litigants visiting court premises were the core elements of this Strategy.

After his retirement from service, he worked as Provincial Team Leader in the FCDO/UKAID funded Subnational Governance Program for improving resource generation, public finance management and upscaling local governance system. In 2020, the Government of Khyber Pakhtunkhwa once again availed his services as Chief Commissioner, Right to Public Services Commission to lead this good governance institution obligated with monitoring 80 notified services delivered by 13 institutions and ensuring timeliness, transparency and good quality. He continued in this role till December, 2023.

Most recently he served as Registrar Supreme Court of Pakistan.