Denny Walling was a professional baseball player who played for 17 seasons in the Major League Baseball (MLB). He was born on April 17, 1954, in Neptune, New Jersey, and attended Clemson University, where he played college baseball.

Walling was drafted by the Oakland Athletics in the first round of the 1975 MLB draft. He made his MLB debut on September 6, 1975, and played for the Athletics until 1977. He then played for the Houston Astros from 1977 to 1985, the St. Louis Cardinals from 1986 to 1988, and the Texas Rangers from 1989 to 1992.

Walling was primarily a third baseman and outfielder, but he also played first base and designated hitter. He was known for his versatility and his ability to hit for average. He had a career batting average of .271, with 80 home runs and 597 runs batted in (RBIs).

Walling played in two World Series during his career. In 1980, he played for the Astros in the World Series against the Philadelphia Phillies. He hit a home run in Game 2 of the series, but the Astros lost in six games. In 1987, he played for the Cardinals in the World Series against the Minnesota Twins. The Cardinals lost in seven games.

After retiring from baseball, Walling became a coach. He was a hitting coach for the Astros from 1997 to 2002 and again from 2010 to 2012. He was also a hitting coach for the Baltimore Orioles in 2004 and the Seattle Mariners in 2005.

Walling was inducted into the Clemson University Athletic Hall of Fame in 1989. In 2017, he was inducted into the Texas Baseball Hall of Fame.

Overall, Denny Walling had a successful career in the MLB, playing for four different teams and earning a reputation as a versatile and reliable player. He also had success as a coach, helping to develop the hitting skills of numerous players.