Smith Thompson was born in New York. He attended Princeton and taught school briefly upon graduating. He read law and entered practice shortly thereafter.
Thompson served in the state legislature and then won an appointment to the state's highest court, where he served for 16 years (four of those as chief justice).
Thompson always held ambition for the presidency. He accepted Monroe's nomination to the Supreme Court when Van Buren captured the presidential nomination in 1824. Seeking a taste for partisan politics, Thompson campaigned unsuccessfully for governor of New York in 1828 while on the Court.