Haitian Vodou ("voodoo" is the term used primarily to distinguish Louisiana voodoo, which is different) did originate in west Africa (the primary source of slaves for the Atlantic slave trade). Vodou is conceptualized as a syncretic mix of traditional African religious practices mixed with distinctly New World elements.

Vodou is descended from several different west African religious traditions. A French man named Mederic Louis Elie Moreau de Saint-Mery traced the origin of Vodou to Dahomey (roughly modern Benin) and Kingdom of Arada Arada. Vodou has its origins among the Fon people (Dahomey people) in Benin, Nigeria, and Togo. These areas are thought to be ancestral to modern day vodou.

However, modern day Vodou as its practiced in Haiti and elsewhere in the African diaspora, is quite distinct from African traditional religions. It is certainly has African roots, but it has also been profoundly influenced by Catholicism and the experiences of slaves.

Sources:

• Murrell 2010 is a good review of several Afro-Atlantic religions, including vodou
• Tann 2012
• Also, if you are interested in the topic, I can't recommend Mama Lola enough. It's an easy read about vodou practitioners in New York.