Dennis Bennett, a left-handed pitcher, played in Major League Baseball during the 1960s. Born on October 5, 1939, in Oakland, California, Bennett began his professional career with the Philadelphia Phillies. He made his MLB debut on June 12, 1962, against the St. Louis Cardinals. In his rookie season, Bennett quickly established himself as a reliable starter for the Phillies, finishing the year with a 9-9 record and a 3.81 ERA.

The 1963 season saw Bennett improve his performance on the mound. He became an integral part of the Phillies' pitching rotation, posting a 9-5 record with a 2.64 ERA. His efforts helped the team remain competitive in the National League. Bennett's ability to deliver strong performances in crucial games earned him respect among his teammates and opponents alike.

In 1964, Bennett continued to be a key player for the Phillies. He played a vital role in the team's pursuit of the National League pennant. That year, he achieved a 12-14 record with a 3.68 ERA. Despite the Phillies' infamous late-season collapse, Bennett's contributions throughout the season were noteworthy. His performance on the mound was characterized by his effective use of a fastball and curveball, which kept hitters off balance.

Bennett's tenure with the Phillies came to an end after the 1964 season when he was traded to the Boston Red Sox. In Boston, he continued to demonstrate his pitching skills. During the 1965 season, Bennett recorded a 9-8 record with a 3.70 ERA. His time with the Red Sox, however, was marred by injuries that limited his effectiveness and playing time.

The following year, Bennett was traded to the New York Mets. His stint with the Mets was brief, as he struggled to regain his form. In 1967, Bennett was traded once again, this time to the Chicago Cubs. His time with the Cubs was short-lived, and he found himself moving to the California Angels later that year. With the Angels, Bennett managed to find some stability, finishing the season with a 1-2 record and a 4.40 ERA.

Bennett's final season in the majors came in 1968 with the California Angels. He appeared in 15 games, primarily as a relief pitcher, and posted a 1-3 record with a 5.20 ERA. After the 1968 season, Bennett retired from professional baseball.

Throughout his career, Dennis Bennett played for several teams, adapting to different roles as a starter and reliever.