Ellen is an Advocate and Solicitor of the Supreme Court of Singapore, after she was called to the Bar on 14 January 1981.
In 1984, Ellen set up her sole-proprietorship law firm, Ellen Lee and Company, and after 21 years of successful practice, she merged it with M/s Ramdas & Wong in 2005 to become their Consultant in preparation for the 2006 General Elections.
She was elected twice as a Member of Parliament for Sembawang GRC (Woodlands) in 2006 and 2011 respectively.
She retired from politics in August 2015.
During her tenure as MP, she held many appointments. More prominently, she was the Chairman of the Singapore-Europe Parliamentary Friendship Group and a member of the Commonwealth Parliamentary Association's Women Parliamentarian Executive Committee.
Ellen was also Vice-Chairman of the Government Parliamentary Committee (GPC) for the Ministries of Defence and Foreign Affairs and concurrently a member of the GPC for Health. She was also a member of the GPC for the Ministries of Law & Home Affairs and the then Community, Youth and Sports (now Ministry of Social & Family Development).
Ellen was an ex-officio in the Ngee Ann Kongsi Board of Directors from 2006 to 2015.
Ellen was also appointed Board Member of the Land Transport Authority from 2011 to 2017 and was also Chairman of LTA’s Finance and Establishment Committee and a Member of LTA’s Risk Management Committee.