A Bachelor of Arts is an undergraduate academic degree awarded for a courses taken that generally lasts three years in the UK or four years in North America, except for Quebec where the degree takes three years after graduation from a provincial CEGEP programme. This was also possible in Ontario until the elimination of OAC.
In North America, a Bachelor of Arts degree usually requires a student to take a majority of their courses (usually 1/2 or 3/4) in the arts, namely social sciences, humanities, music, or fine arts. Universities plan the Arts Bachelor degree as a liberal arts schedule.
In the UK, usage varies: most universities maintain an Arts/Science distinction but some, e.g. Oxford and Cambridge traditionally award(ed) B.A.s (which automatically leads to an M.A after 4 years) to undergraduates regardless of subject. Most of the ancient Scottish universities award an M.A. to arts undergraduates but a B.Sc to science undergraduates.
A Bachelor of Arts receives the designation A.B. or B.A. for a major/pass degree and A.B. (Hon.) or B.A. (Hons) for an honours degree.