Steven Daniel Shell (born March 10, 1983 in Longview, Texas) is a Major League Baseball pitcher with the Seattle Mariners organization. He made his major league debut on June 22, 2008.

Shell was drafted straight out of high school in the 3rd round of the 2001 amateur draft by the Anaheim Angels. Shell pitched in the Angels organization from 2001–2007. He became a minor league free agent after the 2007 season and signed a minor league contract with the Washington Nationals. On July 11, 2008, he set the Nationals' record for the longest save in club history. He pitched 3 scoreless innings against the Astros to get the record as well as his first career save. On April 29, 2009 Shell refused a minor league assigment and became a free agent. On May 2, Shell signed a minor league deal with the Seattle Mariners.