Brantley is a lawyer by profession and has acted in several notable cases involving international litigation . He attended secondary school at Charlestown Secondary School. He completed his higher education at the University of the West Indies where he graduated with a Bachelor of Laws, Upper Second Class Honors. He then attended the Norman Manley Law School where he received a Legal Education Certificate of Merit. He completed his studies at St Catherine's College, a college of the University of Oxford in the United Kingdom (which he attended as a Commonwealth Scholar) where he completed a Bachelor of Civil Law. Brantley has been admitted to the bar in St Kitts and Nevis, Anguilla, Grenada, Antigua and Barbuda and Dominica.