Stargell was born in Earlsboro, Oklahoma, but later moved to Florida with an aunt after the divorce of his parents. Later he returned to California to live with his mother. He attended Encinal High School, where his baseball teammates included future MLB players Tommy Harper and Curt Motton. Stargell signed with the Pittsburgh Pirates organization and entered minor league baseball in 1959.
Stargell played for farm teams in New Mexico, Iowa and Texas. While on the road with those teams, Stargell was not allowed to stay in the same accommodations as the white players. Lodging for black players was located in the poor black areas of those towns. While in Plainview, Texas, he was accosted at gunpoint by a man who threatened his life if he played in that night's game. Stargell played and nothing came of the incident. He might have quit baseball over the racial difficulties that he experienced, but he was encouraged by letters he received from friend and baseball scout Bob Zuk.
Stargell made his major league debut at the end of the 1962 season. Beloved in Pittsburgh for his style of play and affable manner, Stargell hit 7 of the 16 balls ever hit out of Forbes Field and several of the upper-tier home runs at its successor, Three Rivers Stadium. Though he became quickly known as Willie Stargell, his autograph suggests that he preferred his given name, Wilver. Biographer Frank Garland relates that Stargell's family and friends called him Wilver and that Dodgers broadcaster Vin Scully also made a point of using Stargell's given name. Scully said that, because he used the name Wilver, he became Stargell's mother's favorite broadcaster.
Standing 6 feet 3 inches, Stargell seemed larger, with his long arms and unique bat-handling practice of holding only the knob of the bat with his lower hand combining to provide extra bat extension, Stargell's swings seemed designed to hit home runs of the Ruthian variety. When most batters would use a simple lead-weighted bat in the on-deck circle, Stargell took to warming up with a sledgehammer, adding another layer of intimidation. While standing in the batter's box, he would windmill his bat until the pitcher started his windup.
Stargell hit the first home run at Shea Stadium in the first game played in that stadium on April 17, 1964. He made his first of seven trips to the All-Star Game that year. He returned to the All-Star Game the next two seasons, hitting over 100 runs batted in (RBI) in both years.
Frequent offseason conditioning problems came to a head in 1967, when Stargell showing up to spring training at a weight of 235 pounds. The team made him diet to get down to a weight of 215 pounds. His batting average dropped more than .040 points that season; his home run total was reduced from 33 in 1966 to 20 in 1967. The team had a personal trainer work with Stargell before the 1968 season to get him in the best shape of his career, but Stargell had a bad season and manager Larry Shepard criticized Stargell's physique as too muscular.
Stargell won the first of his two home run titles in 1971; his 48 edged out Hank Aaron's 47 on the final week of the season and, to date, trail only Ralph Kiner's 54 and 51 in 1949 and 1947 respectively for most by a Pirate in one season. He was a member of the Pirates' World Championship team, the Pirates defeating the Baltimore Orioles in seven games. The Pirates lost the first two games of that series, which Stargell said that media began referring to as "the St. Valentine's Day Massacre" before Pittsburgh's comeback.
In 1973 Stargell achieved the rare feat of simultaneously leading the league in both doubles and homers. Stargell had more than 40 of each; he was the first player to chalk up this 40-40 accomplishment since Hank Greenberg in 1940; other players have done so since (notably Albert Belle, the only 50-50 player). Stargell won his second home run title that year, edging out three Atlanta Braves: Davey Johnson's 43, Darrell Evans' 41 and Aaron's 40. In 1977, Stargell hit his 400th career home run on June 30 against the Philadelphia Phillies.
Stargell mans first base, 1979
Stargell originated the practice of giving his teammates embroidered "Stargell stars" for their caps after a nice play or a good game. The practice began during the turbulent 1978 season, when the Pirates came from fourth place and 11.5 games behind in mid-August, to challenge the first-place Philadelphia Phillies for the division title. The season was scheduled to end in a dramatic, four-game showdown against the Phillies in Pittsburgh, in which the Pirates had to win all four games to claim the title. Following a Pirate sweep of the Friday-night double-header, Stargell belted a grand slam in the bottom of the first inning of the season's penultimate game to give the Pirates an early 4-1 lead, although the Pirates would relinquish that lead later in the game and fall two runs short after a four-run rally in the bottom of the ninth inning, thus eliminating themselves from contention for the pennant. Stargell called that 1978 team his favorite team ever, and predicted that the Pirates would win the World Series the following year.
The Pirates did win the World Series in 1979, in a similar style as they had ended the 1978 season: from last place in the NL East at the end of April, the Pirates clawed their way into a first place battle with the Montreal Expos during the latter half of the season. They excited fans with numerous come-from-behind victories along the way (many during their final at-bat) to claim the division pennant on the last day of the season. At his urging as captain, the team adopted the Sister Sledge hit song "We Are Family" as the team anthem. Then his play on the field inspired his teammates and earned him the MVP awards in both the NLCS and the World Series. Stargell capped off the year by hitting a dramatic home run in Baltimore during the late innings of a close Game 7 to seal a Pirates championship. The home run was his third of the Series and, coincidentally, credited Stargell with the winning runs in both Game 7's of the two post-season meetings between the Pirates and the Orioles (1971 and 1979). The 1979 World Series victory also made the Pirates the only franchise in baseball history to twice recover from a three-games-to-one deficit and win a World Series (previously they had done so in 1925 against the Washington Senators). For the Series, Stargell went 12-for-30; along with his three home runs, he also recorded four doubles for 25 total bases, which remains tied as a World Series record, Reggie Jackson having set it in the 1977 World Series, and his seven extra-base hits (3 HRs and 4 doubles) in the 1979 World Series also set a record.
Stargell played until 1982, but he never appeared in more than 74 games after 1979. He retired with 475 home runs despite playing much of his career at Forbes Field, whose deep left-center field distance was 457 feet. Hall of Famer Roberto Clemente estimated, perhaps generously, that Stargell hit 400 fly balls to the warning track in left and center fields during his eight seasons in the park. The short fence in right field (300 feet to the foul pole) at Forbes Field was guarded by a screen more than 20 feet high which ran from the right-field line to the 375-foot mark in right center. Three Rivers Stadium, a neutral hitter's park, boosted Stargell's power numbers. The Pirates moved into Three Rivers in mid-1970, and he hit 310 of his 475 career home runs from 1970 until his retirement, despite turning 30 in 1970. Stargell's two home run titles came in his first three years at Three Rivers.
At one time, Stargell held the record for the longest homer in nearly half of the NL parks. On August 5, 1969, Stargell hit a home run off of Alan Foster that left the stadium and measured 507 feet, the longest home run ever hit at Dodger Stadium. He hit a second home run out of Dodger Stadium on May 8, 1973 against Andy Messersmith, measured 470 feet. Dodger starter Don Sutton said of Stargell, "I never saw anything like it. He doesn't just hit pitchers, he takes away their dignity." Only two other home runs have been hit out of Dodger Stadium.
On June 25, 1971, Stargell hit the longest home run in Veterans Stadium history during a 14-4 Pirates win over the Philadelphia Phillies. The spot where the ball landed (the shot came in the second inning and chased starting pitcher Jim Bunning) was eventually marked with a yellow star with a black "S" inside a white circle until Stargell's 2001 death, when the white circle was painted black. The star remained in place until the stadium's 2004 demolition. In 1978, against Wayne Twitchell of the Montreal Expos, Stargell hit the only fair ball ever to reach the upper deck of Olympic Stadium. The seat where the ball landed (the home run was measured at 535 feet) has since been painted in yellow, while the other seats in the upper deck are red.
Bob Prince, the colorful longtime Pirate radio announcer would greet a Stargell home run with the phrase "Chicken on the Hill". This referred to Stargell's ownership of a chicken restaurant in Pittsburgh's Hill District. For a time, whenever he homered, Stargell's restaurant would give away free chicken to all patrons present in the restaurant at the time of the home run, in a promotion dubbed "Chicken on the Hill with Will". Prince himself once promised free chicken to listeners if Stargell hit a home run; Stargell did homer and Prince picked up a $400 bill at the restaurant.
Stargell signs autographs during his retirement in 1983.
After retirement, Stargell spent several years as a coach for the Atlanta Braves. He was the first minor league hitting coach for Chipper Jones. He was inducted into the Baseball Hall of Fame in 1988, his first year of eligibility. He had an awkward interaction with the Pirates that season when the team wanted to schedule a Willie Stargell Night to honor his Hall of Fame election. Stargell refused to participate in the team's plans, still stinging from the team's refusal to even consider him for its managerial job that season.
In the 1985 trial of alleged cocaine dealer Curtis Strong, Stargell was accused by Dale Berra and John Milner (both former Pirates teammates) of distributing "greenies" (amphetamines) to players. Berra said that he obtained amphetamines from Stargell and Bill Madlock; he said he could get them from Stargell "on any given day I asked him for one." Stargell strongly denied these charges. Commissioner Peter Ueberroth later cleared Stargell and Madlock of any wrongdoing.
Stargell returned to the Pittsburgh club in 1997 as an aide to Cam Bonifay, the team's general manager. He also worked as a special baseball adviser to Pirates owner Kevin McClatchy, who called Stargell "the ultimate class act". Stargell was hospitalized for three weeks in 1999 to treat undisclosed medical problems with one of his organs. A source close to the Pirates blamed Stargell's health issues on his weight gain after retiring as a player. Stargell lost some of that weight, but gained weight again while working for the Pittsburgh front office.
After years of suffering from a kidney disorder, he died of complications related to a stroke in Wilmington, North Carolina, on April 9, 2001. In his later life, Stargell had also suffered from hypertension and heart failure. A segment of Stargell's bowel was removed more than two years before he died. He had been in the hospital recovering from a gallbladder surgery at the time of his death. On the day he died, a larger-than-life statue of him was unveiled at the Pirates' new stadium, PNC Park, as part of the opening-day ceremonies.
Just two days before his death, on April 7, 2001, he Pittsburgh Pirates unveiled a 12 foot, one ton bronze statue of "Pops" outside the left field of PNC Park. 
After Stargell died, Joe Morgan said, "When I played, there were 600 baseball players, and 599 of them loved Willie Stargell. He's the only guy I could have said that about. He never made anybody look bad and he never said anything bad about anybody."
The Willie Stargell Foundation was established to promote research and treatment for kidney disease. Champion Enterprises sponsors a Willie Stargell Memorial Awards Banquet which raises money for disadvantaged children in Pittsburgh.
Stargell also worked to raise awareness of sickle cell anemia. He formed the Black Athletes Foundation shortly after President Richard M. Nixon identified the disease as a "national health problem" in the early 1970s. For a decade, BAF, renamed the Willie Stargell Foundation, raised research money and public awareness about the disease. Starting in 1981, sickle cell awareness and fundraising was gradually being assumed by The Sickle Cell Society Inc. The Willie Stargell Foundation transitioned to raising money for treatment of and research into kidney disease.