Arizona acquired Trumbo from the Los Angeles Angels in December in a three-team trade that included the Chicago White Sox. Trumbo hit 34 home runs last season and 32 in 2012. He has 95 home runs since reaching the major leagues in 2011.
A first baseman much of his time with the Angels, Trumbo is expected to play left field for Arizona.
Other than Paul Goldschmidt with 36 homers, the Diamondbacks had no one hit more than 14 last season.
Trumbo was Arizona's last player in arbitration. He had asked for a raise from $540,000 to $5.85 million when the sides swapped proposed salaries last month, and the Diamondbacks had offered $3.4 million.