This is a list of adult fiction books that topped The New York Times Fiction Best Seller list in 2009.
The most popular books of the year were The Lost Symbol, by Dan Brown and The Associate, by John Grisham with respectively 7 and 4 weeks at the top. The author James Patterson was at the top for four different books (8th Confession, Swimsuit, Alex Cross's Trial and I, Alex Cross).
References
The New York Times Fiction Best Sellers of 2009 Wikipedia(Text) CC BY-SA