Ho is the eldest of four children of retired businessman Ho Eng Hong and Chan Chiew Ping. She has two brothers and a sister. Her sister Ho Peng is the chairperson of the Singapore Examinations and Assessment Board while younger brother Ho Sing is executive director of Starhill Global REIT. She met her husband, Lee Hsien Loong, the current Prime Minister of Singapore and eldest son of former Singapore Prime Minister Lee Kuan Yew, while starting out in her career at the Ministry of Defence. They married on 17 December 1985 and have one daughter Xiuqi and three sons Yipeng, Hongyi and Haoyi; Xiuqi and Yipeng are her stepchildren from Lee's first marriage.
Having completed her secondary education at Crescent Girls' School, Ho proceeded to become one of the top students for the ‘A’ level examinations in her cohort at National Junior College, where she was named Student of the Year. She then went to the then-Singapore University (now the National University of Singapore) and graduated in 1976 with a Bachelor of Engineering (Electrical, First Class Honours). In 1982, Ho graduated with a Master of Science (Electrical Engineering) degree from Stanford University.
Ho started her career as an engineer with the Ministry of Defence of Singapore in 1976. In 1983, she became the Director of Defence Material Organisation, the defence procurement agency of the Ministry, and concurrently held the position of Deputy Director of Defence Science Organisation. She joined Singapore Technologies in 1987 as Deputy Director of Engineering, and took on various senior responsibilities before becoming its President and Chief Executive Officer in 1997. She is credited with repositioning and growing the group in the five years that she led it. For instance, she was the architect for the formation and listing of Singapore Technologies Engineering as the largest listed defence engineering company in Asia in 1997, and served as its first Chairman.
Ho joined Temasek Holdings as a Director in January 2002 and became its Executive Director in May 2002. The then-chairman of Temasek Holdings, former Cabinet minister S. Dhanabalan, said Ho was the best person for the job because of "a willingness on her part to take calculated risks". She assumed the role of Chief Executive Officer of Temasek on 1 January 2004. She is widely credited with transforming Temasek, an investment company owned by the Government of Singapore, from a Singapore-focused firm into an active investor in Asia and the world. Today, Temasek owns and manages a net portfolio of S$215 billion (US$173 billion) as at 31 March 2013. Ho has a strong track record in public service, notably for having served as chairman of the Singapore Institute of Standards and Industrial Research, and as deputy chairman of the Productivity and Standards Board, and the Economic Development Board.
In 1995, Ho was conferred the National University of Singapore’s Distinguished Engineering Alumnus Award. She is also an Honorary Fellow of the Institution of Engineers, Singapore.
For her public service, she was conferred the Singapore Public Administration medal (silver, 1985) and the Public Service Star (1996) award by the Singapore Government.
Ho has appeared in many rankings of the most powerful and influential people in the world. In 2007, Ho was picked as one of the "100 most influential men and women" who shaped the world by TIME Magazine. Also in 2007, Forbes magazine ranked her third in its annual list of the world's most powerful women, behind German Chancellor Angela Merkel and China's Vice-Premier Wu Yi. Ho had climbed 33 spots from 36th place in the previous year’s list.
In 2011, Ho was included in the ‘50 Most Influential’ ranking by Bloomberg Markets magazine.
In 2013, Ho was ranked ninth on the Public Investor 100 ranking compiled by the Sovereign Wealth Fund Institute.
As of 2014, she is listed as the 59th most powerful woman in the world by Forbes. In June, Ho was also awarded the 2014 Asian Business Leaders Award. The annual Asia House award recognises individuals who embody the 'Servant Leader' - economic success and professional excellence accompanied by moral leadership and service to society. Asia House is a centre of expertise on Asia and the leading pan-Asian organisation in the UK. She became the 30th most powerful woman in 2016.
In her personal capacity, Ho Ching supports various community service and charitable organisations. She has particular interest in special needs education, healthcare and the welfare and development of children. She is the Patron of Assisi Hospice, and the founding Chairman of Trailblazer Foundation Ltd, an IPC charity which provides funding for education, health, sports and community welfare. In March 2014, Ho was inducted into the Singapore Council of Women’s Organisations' Singapore Women’s Hall of Fame, which honours outstanding women of Singapore in all fields of endeavour.