Ennis was born to George and Agnes Ennis in the Crescentville section of Philadelphia.
 He played baseball and football at Olney High School and was mentioned as an all-state fullback.
 The Philadelphia Phillies scout Jocko Collins came to watch one of Ennis's high school classmates pitch.
 When Ennis hit two long home runs, Collins tried to recruit him but Ennis was hesitant, worried that he was not ready, and unsure that he wanted to pursue a baseball career.
 In August 1942, Ennis finally signed with Collins to play with the Phillies Canadian–American League team, but the league suspended operation for World War II.
 Ennis signed with Collins again in March 1943 and hit .348 with 19 home runs and 16 triples for the Phillies' Trenton, New Jersey Interstate League team.
 In September 1943, Philadelphia wanted to call Ennis to the major leagues, but he went into the United States Navy instead.
 Ennis saw military action in the Pacific Theater and also toured with a baseball team that included Billy Herman, Johnny Vander Meer and Schoolboy Rowe.

He joined the United States Navy on September 29, 1943 and was assigned to Sampson Naval Training Station, New York where he graduated as a signalman from "A" school at Sampson and then posted to the Hawaiian Sea Frontier.
When the Navy learned that Ennis was associated with the Phillies, they assumed he was a major leaguer and invited him to fill one of the vacancies while in Honolulu.
He was included on the Navy's Western PAC Tour of many Pacific Islands in 1944–1945.
Ennis looked very good at the plate in the few exhibition games which immediately preceded the tours.
His slugging prompted Dan Topping, new owner of the New York Yankees and a fellow serviceman at Pearl Harbor, to offer him $25,000 to sign with the Yanks.
The Phillies had paid Ennis only $50 to sign.

His naval rank was Petty Officer Third Class.
Most of his service was on the island of Guam after the winter tour.
Playing with and against major leaguers on the tours was equivalent of a minor league apprenticeship for Ennis.
After the tours he was assigned to a fleet recreation billet at Gab Gab Beach on Guam and stayed on the island for one year.
He did not make it back to the States as soon as some of the others because he did not have enough points built up.
He finally returned stateside through San Diego on the USS Wakefield.
Ennis was discharged from the Navy on April 5, 1946 and joined the major league Phillies about a week later.

Player-manager Ben Chapman delayed Ennis's debut since he had missed spring training, and then had him pinch-hit on April 28 against the Boston Braves – a groundout to shortstop.
 Chapman gave Ennis the starting job in left field, a weak spot in the Phillies lineup.
 On May 5, Ennis hit his first home run – a three-run shot in the first inning – and then his second, both in the second game of a doubleheader.
 His favorite moment was on Del's birthday, June 8, 1946, hitting a single to break up a perfect game with only four outs remaining against Red Barrett.
Barrett of the Boston Braves had retired 22 batters in a row before Ennis' single.
Olney residents held a Del Ennis Night at Shibe Park with 36,356 in attendance and an estimated 20,000 were turned away.
 Ennis singled with the bases loaded to drive in two runs in the first inning against the Cardinals and the Phillies won.
 His average raised over .300 until a slump in July.

In his early career, Ennis was noted not only for his home runs, runs batted in and hard line drives, but also good outfield play and fast, hard baserunning.
 Eleven weeks after his debut, Ennis became the first Phillies rookie to make an All-Star team on the strength of a strong throwing arm and lively bat.
He also became the first ever Sporting News Rookie Award winner, and finished eighth in the Most Valuable Player Award voting after batting .313 with 17 home runs and 73 RBI and placing second in the National League in slugging average (.485) behind Musial.

Ennis showed his power in 1948, driving in 95 runs with 30 home runs – a Phillies record for right
Ennis was born to George and Agnes Ennis in the Crescentville section of Philadelphia.  He played baseball and football at Olney High School and was mentioned as an all-state fullback.  The Philadelphia Phillies scout Jocko Collins came to watch one of Ennis's high school classmates pitch.  When Ennis hit two long home runs, Collins tried to recruit him but Ennis was hesitant, worried that he was not ready, and unsure that he wanted to pursue a baseball career.  In August 1942, Ennis finally signed with Collins to play with the Phillies Canadian–American League team, but the league suspended operation for World War II.  Ennis signed with Collins again in March 1943 and hit .348 with 19 home runs and 16 triples for the Phillies' Trenton, New Jersey Interstate League team.  In September 1943, Philadelphia wanted to call Ennis to the major leagues, but he went into the United States Navy instead.  Ennis saw military action in the Pacific Theater and also toured with a baseball team that included Billy Herman, Johnny Vander Meer and Schoolboy Rowe.
He joined the United States Navy on September 29, 1943 and was assigned to Sampson Naval Training Station, New York where he graduated as a signalman from "A" school at Sampson and then posted to the Hawaiian Sea Frontier. When the Navy learned that Ennis was associated with the Phillies, they assumed he was a major leaguer and invited him to fill one of the vacancies while in Honolulu. He was included on the Navy's Western PAC Tour of many Pacific Islands in 1944–1945. Ennis looked very good at the plate in the few exhibition games which immediately preceded the tours. His slugging prompted Dan Topping, new owner of the New York Yankees and a fellow serviceman at Pearl Harbor, to offer him $25,000 to sign with the Yanks. The Phillies had paid Ennis only $50 to sign.
His naval rank was Petty Officer Third Class. Most of his service was on the island of Guam after the winter tour. Playing with and against major leaguers on the tours was equivalent of a minor league apprenticeship for Ennis. After the tours he was assigned to a fleet recreation billet at Gab Gab Beach on Guam and stayed on the island for one year. He did not make it back to the States as soon as some of the others because he did not have enough points built up. He finally returned stateside through San Diego on the USS Wakefield. Ennis was discharged from the Navy on April 5, 1946 and joined the major league Phillies about a week later.
Player-manager Ben Chapman delayed Ennis's debut since he had missed spring training, and then had him pinch-hit on April 28 against the Boston Braves – a groundout to shortstop.  Chapman gave Ennis the starting job in left field, a weak spot in the Phillies lineup.  On May 5, Ennis hit his first home run – a three-run shot in the first inning – and then his second, both in the second game of a doubleheader.  His favorite moment was on Del's birthday, June 8, 1946, hitting a single to break up a perfect game with only four outs remaining against Red Barrett. Barrett of the Boston Braves had retired 22 batters in a row before Ennis' single. Olney residents held a Del Ennis Night at Shibe Park with 36,356 in attendance and an estimated 20,000 were turned away.  Ennis singled with the bases loaded to drive in two runs in the first inning against the Cardinals and the Phillies won.  His average raised over .300 until a slump in July.
In his early career, Ennis was noted not only for his home runs, runs batted in and hard line drives, but also good outfield play and fast, hard baserunning.  Eleven weeks after his debut, Ennis became the first Phillies rookie to make an All-Star team on the strength of a strong throwing arm and lively bat. He also became the first ever Sporting News Rookie Award winner, and finished eighth in the Most Valuable Player Award voting after batting .313 with 17 home runs and 73 RBI and placing second in the National League in slugging average (.485) behind Musial.
Ennis showed his power in 1948, driving in 95 runs with 30 home runs – a Phillies record for right
Del Ennis