In 2014 she opened her own law firm, after serving as Company Secretary and Head of Corporate Affairs and Projects (Legal) of Cable & Wireless Jamaica Limited. Senator Johnson Smith holds a Master of Laws in Commercial Law from the London School of Economics and Political Science, a Bachelor of Laws from the University of the West Indies, Cave Hill and a Bachelor of Arts in French and International Relations from the University of the West Indies, Mona. She also subsequently completed professional certificates, including areas such as Legal and Diplomatic French in Guadeloupe as well as Negotiation at the Harvard Law School Professional Programme in Boston, Massachusetts.