The 1934 Cincinnati Reds season was a season in American baseball. The team finished eighth and last in the National League with a record of 52–99, 42 games behind the St. Louis Cardinals. Their .344 winning percentage remains the lowest in franchise history and the 99 losses were the worst in franchise history until the 1982 Reds lost 101 games. Because the schedule did not have 162 games at this time, and the Reds only won 52 games this season compared to 1982, when they lost 101 games, when at the same time winning 61 games, nine more than this team, the 1934 Reds are actually a weaker team than the 1982 team, thus making this team the worst in franchise history overall.
 In February 1934, Powel Crosley Jr. purchased the Reds from Sidney Weil. He kept the team from going bankrupt and possibly leaving Cincinnati. General manager Larry MacPhail insisted that Redland Field be renamed in honor of the man who had saved the team. The park was renamed Crosley Field, and Crosley himself took the opportunity to advertise his Crosley automobiles.
 After purchasing the team, the owner hired Red Barber as the Reds play-by-play commentator on WSAI.
 Following the 1933 season, the club fired manager Donie Bush after a 58–94 season. The Reds did not name a replacement until later in the off-season.
 On November 15, 1933, the Reds traded second baseman George Grantham to the New York Giants in exchange for pitcher Glenn Spencer. Spencer had a record of 0–2 with a 5.13 ERA in 17 games with the Giants in 1933. He previously pitched with the Pittsburgh Pirates, and led the league in games finished in 1930 with 22.
 Two days later, on November 17, Cincinnati traded away pitcher Red Lucas and outfielder Wally Roettger to the Pittsburgh Pirates for outfielder Adam Comorosky and second baseman Tony Piet. Lucas, who had been with the Reds since 1926, earned a record of 109–99 and a 3.64 ERA in 257 games with the team. He led the National League in complete games on three occasions (1929, 1931 and 1932), and led the league in shutouts in 1928. Comorosky played in 64 games with the Pirates in 1933, hitting .284 with a home run and 15 RBI. His best season was in 1930, when Comorosky hit .313 with 12 home runs, 119 RBI and leading the league with 23 triples and 33 sacrifice bunts. Piet had an average of .323 with a home run and 42 RBI in 107 games with Pittsburgh in 1933.
 Less than a week later, on November 23, the Reds selected shortstop Gordon Slade off of waivers from the St. Louis Cardinals. Slade struggled in 1933, hitting .113 with 3 RBI in 39 games.
 In December, Cincinnati purchased pitcher Joe Shaute from the Brooklyn Dodgers. Shaute had a 3–4 record with a 4.29 ERA in 41 games with Brooklyn in 1933.
 On December 20, the club acquired infielder Mark Koenig from the Chicago Cubs in exchange for infielders Irv Jeffries and Otto Bluege. Koenig hit .284 with three home runs and 25 RBI in 80 games with Chicago. Koenig was a two time World Series champion, as he was part of the 1927 and 1928 New York Yankees.
 On January 11, the Reds traded away recently acquired Glenn Spencer to the St. Louis Cardinals for catcher Bob O'Farrell and pitcher Syl Johnson. The Reds then named O'Farrell as the player/manager of the team. O'Farrell had previous player/managerial experience, as he led the Cardinals to a 92–61 and a second-place finish in the National League in 1927. As a player, O'Farrell hit .239 with two home runs and 20 RBI in 55 games in 1933. O'Farrell was named the National League Most Valuable Player in 1926. Johnson finished the previous season with a 5–9 record with a 3.46 ERA in 44 games.
 On February 6, Cincinnati selected pitcher Dazzy Vance off of waivers from the St. Louis Cardinals. Vance, who would turn 43 before the season began, had a 6–2 record with a 3.55 ERA in 28 games with the Cardinals in 1933. Vance played with the Brooklyn Dodgers from 1922 to 1932, during which he led the National League in strikeouts in seven consecutive seasons (1922–1928), wins twice (28 in 1924, 22 in 1925), ERA three times (2.16 in 1924, 2.09 in 1928, and 2.61 in 1930), shutouts four times (1922, 1925, 1928, and 1930) and complete games two times (1924 and 1927). Vance was the National League Most Valuable Player in 1924.
 In March, the team purchased pitcher Don Brennan from the New York Yankees. Brennan was 5–1 with a 4.98 ERA in 18 games during his rookie season in 1933 with New York.
 The rebuilding Reds struggled to begin the season, winning only five of their first 24 games to quickly find themselves in last place. On May 12, in a game against the Boston Braves, player/manager Bob O'Farrell submitted a lineup card with the last names of his starting nine in alphabetical order, the only time this has happened in MLB history. Although the Reds got 12 hits with this lineup, they lost 8–2. On May 16, Cincinnati traded pitcher Syl Johnson and outfielder Johnny Moore to the Philadelphia Phillies for pitcher Ted Kleinhans, outfielder Art Ruble and outfielder Wes Schulmerich. Less than a week later, the Reds traded Ruble to the Oakland Oaks of the Pacific Coast League for outfielder Harlin Pool. By the end of May, Cincinnati had a record of 8–27 and was 15.5 games behind the St. Louis Cardinals for first place.
 The Reds played better baseball in June, posting a 13–16 record during the month; however, Cincinnati remained in last place with a 21–43 record, 19.5 games behind the pennant leading New York Giants. On June 25, the Reds lost pitcher Dazzy Vance to the St. Louis Cardinals off of waivers.
 In July, Cincinnati acquired infielder Alex Kampouris from the Sacramento Senators of the Pacific Coast League. Kampouris had a .277 average with 19 home runs with the Senators at the time of the trade.
 On July 27, O'Farrell asked for and was granted his release from the team after the team had a record of 30–60. Coach Burt Shotton was named the interim manager for one game. After a win of 11–2 over the Chicago Cubs on July 28, the Reds named former player Chuck Dressen as manager. Dressen had played with Cincinnati from 1925 to 1931, hitting .273 with 11 home runs and 218 RBI in 630 games. He had previously managed the Nashville Vols of the Southern Association since 1932, although he briefly left the Vols to play with the New York Giants late in 1933.
 Under Dressen, the Reds continued to struggle; in 60 games as manager, the team had a 21–39 record. Overall, Cincinnati finished the season with a 52–99 record, in last place for the fourth consecutive season. The 52 wins tied the 1901 club for the fewest in a season in club history, while the 99 losses and .344 winning percentage were the worst in team history.
 Outfielder Harlin Pool, who was acquired by the Reds during the season, led the team with a .327 batting average while hitting two home runs and 50 RBI in 99 games. Outfielder Chick Hafey hit .293 with a team high 18 home runs in 140 games. First baseman Jim Bottomley hit .284 with 11 home runs, a team high 78 RBI and 11 triples, in 142 games.
 Paul Derringer led the Reds pitching staff, earning a record of 15–21 with a 3.59 ERA in 47 games. He led the Reds with 122 strikeouts and 18 complete games. Benny Frey earned a record of 11–16 with a team best 3.52 ERA in 39 games. Si Johnson led the NL in losses, as he was 7–22 with a 5.22 ERA in 46 games. Johnson had also previously led the NL in losses in 1931.
 
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 Note: Pos = Position; G = Games played; AB = At bats; H = Hits; Avg. = Batting average; HR = Home runs; RBI = Runs batted in
 Note: G = Games played; AB = At bats; H = Hits; Avg. = Batting average; HR = Home runs; RBI = Runs batted in
 Note: G = Games pitched; IP = Innings pitched; W = Wins; L = Losses; ERA = Earned run average; SO = Strikeouts
 Note: G = Games pitched; IP = Innings pitched; W = Wins; L = Losses; ERA = Earned run average; SO = Strikeouts
 Note: G = Games pitched; W = Wins; L = Losses; SV = Saves; ERA = Earned run average; SO = Strikeouts
 LEAGUE CHAMPIONS: Toronto