He began his 19-year Major League Baseball (MLB) career with the 1961 Chicago Cubs but spent most of it as a left fielder for the St. Louis Cardinals.

"[4] Brock grew up as a fan of the Brooklyn Dodgers, the team that included Jackie Robinson, Don Newcombe, and Roy Campanella.

[4] Although he did not play in organized baseball until he reached the 11th grade, he learned much about the sport from listening to Cardinals radio broadcaster Harry Caray describe the way major league hitters stood at the plate.

[4] After attending high school in Mer Rouge, Louisiana, he received academic assistance to attend Southern University in Baton Rouge, but when a low grade in his first semester meant the possibility of losing his scholarship, he decided to try out for the school's baseball team in order to secure an athletic scholarship.

[5] When Brock decided to try for a professional baseball career, he traveled to St. Louis to try out for the Cardinals, but the scout who had recommended him was in Seattle to sign Ray Washburn.

[7] In his rookie season of 1962, Brock became one of four players to hit a home run into the center-field bleachers at the old Polo Grounds in New York City since its 1923 reconstruction.

[8][9] Brock had great speed and base running instincts, but the young right fielder failed to impress the Cubs management, hitting for only a combined .260 average over his first two seasons.

Brock's contributions to the Cardinals' championship season were recognized when he finished in tenth place in voting for the 1964 National League Most Valuable Player Award.

[15] In David Halberstam's book, October 1964, the author stated manager Johnny Keane asked Brock to forgo hitting home runs in favor of stealing bases.

[17] He was hitting for a .328 average by mid-June to earn the role as the starting left fielder for the National League in the 1967 All-Star Game.

[21] After Brock had hit a double, he tried to score standing up on Julián Javier's single to left, but Willie Horton threw him out with a strong throw to home plate.

"Brock pioneered the rolling start," states a later Sports Illustrated article, which also maintains that base-stealing tends to be overrated as a factor in team success.

In 1964, Brock acquired a movie camera and filmed opposing pitchers from the dugout to study their windups and pickoff moves to detect weaknesses he could exploit.

[33] On August 13, 1979, in a game against the team that traded him, the Chicago Cubs, Brock became the fourteenth Major League Baseball player to garner 3,000 hits.

[42] In the wake of his record-setting 118 stolen bases during the 1974 season, Brock was named the winner of the Roberto Clemente Award in March 1975, for best exemplifying the game of baseball both on and off the field.

[45] In December 1979, he was named as the recipient of the Hutch Award, given to the player who best exemplifies the fighting spirit and competitive desire of Fred Hutchinson.

[46] On September 9, 1979, the St. Louis Cardinals retired Brock's jersey number 20, an honor that had been bestowed upon only three other players; Stan Musial, Dizzy Dean, and Bob Gibson.

[56] He briefly worked as a color analyst for Monday Night Baseball on ABC in 1980, and for Chicago White Sox telecasts the following year.

He also lent his name to a unique rainhat, shaped like a miniature umbrella, meant to be worn at games during showers in lieu of retreating to the concourse.

[57] During the 1980s and 1990s, Brock was a spring training baserunning instructor with various MLB clubs, including the 1982 Cardinals, 1987 Minnesota Twins, 1988 Los Angeles Dodgers and 1993 Montreal Expos.

[58] Brock and his wife, Jackie, were both ordained ministers serving at Abundant Life Fellowship Church in St. Louis, and he was a director on the board of YTB International.

[59] Brock's speed was referred to in the song "Check the Rhime" by the pioneering "jazz rap" hip-hop ensemble A Tribe Called Quest.

On December 5, 2006, he was recognized for his accomplishments on and off of the field when he received the Bobby Bragan Youth Foundation Lifetime Achievement Award.

[62] Brock announced on April 13, 2017, that he was diagnosed with multiple myeloma, a blood cancer that starts in the bone marrow's plasma cells.

[63] On July 28, 2017, Brock and his wife said they had received word from Mercy Hospital's doctors that, according to their blood tests, the cancerous cells were gone.