Derrick Dalley was born in Twillingate, Notre Dame Bay. He spent his early childhood in Springdale and later returned to Twillingate where he completed high school at J.M.Olds Collegiate. He graduated from Memorial University in 1987 with Bachelor Degrees in Arts and Education which included a political science major. In 1992, he completed a Masters Degree in Guidance and Counselling at the University of New Brunswick.

Mr. Dalley started his career as a social worker in Twillingate. After a year he moved to Education and became the guidance Counsellor in Baie Verte. For seven years Derrick continued in his role as guidance counselor for several schools on the Baie Verte Peninsula before moving to Twillingate in 1995. He continued his career in education in various capacities, including principal of Inter Island Academy of New World Island and guidance counsellor and principal of J. M. Olds Academy of Twillingate.

Mr. Dalley has always been very active in the area of sports, having participated in many sports including hockey and softball. He has spent much of his free time coaching and teaching hockey and working with students who are actively involved in school life.

Mr. Dalley was first elected as a member of the House of Assembly for the District of The Isles of Notre Dame in the election of October 9, 2007. He was appointed as Vice-Chair of the Public Accounts Committee on January 9, 2008.

On April 9, 2009, Mr. Dalley was appointed Parliamentary Secretary to the Minister of Education.

Derrick lives in Twillingate with his wife Anne Marie and two children Zachary and Samantha.