The uniforms worn by Major League Baseball teams have changed significantly since professional baseball was first played in the 19th century. Over time they have adapted from improvised, wool uniforms to mass-produced team brands made from polyester. The official supplier for Major League Baseball uniforms is Nike, who has held the contract since 2020.
Uniforms Early days
The official rules of MLB require that all players on a team wear matching uniforms, although this rule was not enforced in the early days. Originally, teams were primarily distinguished by the colors of their stockings and the success of the Cincinnati Red Stockings popularized the adoption of sock color as the explicit identity of the club. The 1876 Chicago White Stockings actually wore caps of different colors. In 1882, the National League assigned stocking colors to the member clubs: red for Boston, white for Chicago, gray for Buffalo, blue for Worcester, gold for Detroit, green for Troy, and so on. That year, the league also assigned jersey and cap colors, but by player position rather than by club.
Changes Traditionally, when playing at home, teams wore uniforms that were mostly white with trim in team colors and when playing away, they wore uniforms that were mostly gray with trim in team colors. Aside from the obvious need to distinguish one team from the other, conventional wisdom held that it was more difficult to properly launder uniforms while on a road trip, thus the "road grays" helped to hide accumulated soil. This convention continued well after its original premise was nullified by the issuance of multiple uniforms and the growth of the laundromat industry.
Starting in the 1970s, with the advent of synthetic fabrics, teams began using more color in their uniforms, notably the Kansas City Athletics in 1963, the San Diego Padres' brown-and-yellow scheme beginning in 1969, and the Houston Astros' rainbow stripes in the mid-1970s. This era also saw the emergence of powder blue as a primary road color, with teams such as the Kansas City Royals, Minnesota Twins, Montreal Expos and Philadelphia Phillies popularizing the look. Pullover jerseys also became a trend, with the Pittsburgh Pirates first popularizing the look in 1970, going as far as using multiple combinations of differently colored jerseys and trousers and caps (with the options of black, yellow, and white with pinstripes). At one point in the 1970s, the Cleveland Indians had an all-red uniform. From 1976 to 1981, the Chicago White Sox at times had an all-blue uniform, part of a radical style which included a jersey with a large collar, worn untucked—and, for two games in 1976, shorts. The pullover era peaked in 1978, when all but four teams had at least one pullover jersey. The only teams who continued to wear more traditional uniforms were the New York Yankees, Los Angeles Dodgers, Philadelphia Phillies and Montreal Expos. With colored tops becoming popular during this period, some teams stopped wearing road gray uniforms, mainly due to the fact that these uniforms are easily distinguishable. By the mid-1980s, however, the road grays would return, and the trend of colored jerseys would not return until the mid-1990s. As for pullovers, the Cincinnati Reds became the last team to wear them regularly, returning to a more traditional design after 1992. The pullover style wouldn't return until 2024 when the Washington Nationals wore a white pullover alternate.
Most uniform tops featured sleeves, but in 1940, the Chicago Cubs introduced the vest/undershirt combination for three seasons. The traditional uniform top was worn but the sleeves were removed, exposing the colored undershirt. The Cubs' experiment was short-lived, but other teams tried to incorporate uniform vests into the rotation. The Cincinnati Reds went through several brief periods wearing vests, the last coming in 2006. The Pittsburgh Pirates won the 1960 World Series while wearing vests, and continued to do so on-and-off until 2008. In the 1990s and early 2000s, almost half of Major League teams incorporated vests to their uniforms, the most prominent being the Florida Marlins and Arizona Diamondbacks who respectively won the and World Series while wearing vests. Teams such as the Anaheim Angels and Toronto Blue Jays incorporated a 'faux-vest' uniform, featuring contrasting color sleeves to simulate the look. However, merchandising concerns led to the demise of the uniform vest, with the Colorado Rockies in 2021 being the last team to wear a uniform vest.
In his comedy routine "Baseball & Football", George Carlin observes that in baseball, as compared to football, the manager is required to wear the same uniform the players do. However, this was actually not true in the early years of the game. Player-managers were common, but non-playing managers whose realm was strictly the dugout often wore business suits, a common occurrence at the time. Retired players who became managers were more likely to continue to wear a baseball uniform (John McGraw, for example, although he later switched to wearing a suit), especially if they were also active on the coaching lines; managers often doubled as third-base coach. By the late 1940s, nearly all managers were wearing baseball uniforms. Connie Mack was the last major league manager to wear a suit in the dugout until his retirement in the early 1950s; however, in contrast to the uniform-wearing managers, Mack rarely if ever stepped onto the field during a game; instead he sent uniformed coaches onto the field when a managerial presence outside the dugout was required.
Modern era Starting in the 1990s, MLB clubs began heavily marketing licensed goods, such as caps and uniform jerseys to the public and this has resulted in a wide array of uniforms for each team. Now, some teams have not only a basic home uniform and away uniform, but also special "Sunday game" uniforms and uniforms worn only during batting practice and uniforms worn on singular events. From time to time, individual MLB teams have held "Turn Back the Clock Day", regularly scheduled games in which teams donned uniforms in styles their predecessors wore generations earlier (sometimes called "throwback" uniforms), or other antique-style uniforms such as those of Negro league clubs. The Los Angeles Dodgers occasionally use the livery of their original identity as the Brooklyn Dodgers, on special anniversaries or occasions, for example such as in honor of the retirement of Jackie Robinson's uniform number 42 throughout professional baseball (on April 15 – the anniversary of Robinson's MLB debut – entire teams often wear 42). In addition, in 1999, MLB staged "Turn Ahead the Clock Day", in which teams wore uniforms that were built around a "futuristic" theme, including science fiction references, such as the New York Mets being referred to as the "Mercury Mets."
For example, from 1999 to 2006 the Cincinnati Reds wore a variety of caps: all red, red crown and black bill, black crown and red bill, and all black, but since 2007, only the all-red (home) and red crown/black bill (away) are used. In contrast from the pre-1970s era, in which there usually was just one home uniform and one road uniform (with certain exceptions, such as Oakland and Pittsburgh's complex combinations), today choices of what combination of uniform elements are worn are now sometimes left up to players. In some cases, aspects of the uniform that are considered official are rarely worn, such as the New York Mets' blue home cap, with the orange button, which was rarely seen on the field in the years 1998–2012 in favor of an "alternate" black-and-blue cap. The Mets added the orange button on their blue caps in 1995. Through 2025, the New York Yankees and Los Angeles Dodgers wear uniforms which have changed little since the 1930s – while the Detroit Tigers have worn essentially the same home uniform during that span (only the Tigers, Yankees, and Chicago White Sox retain the once-common practice of placing the cap insignia on their home whites, though many teams, including the White Sox, do so on alternate jerseys), their road grays have changed more often. The Dodgers did, however, started wearing two road uniforms regularly in 2014 – one which featured the team name and another which featured the city name; the former is currently their primary road uniform. The Tigers, who for one game in 1995 wore an alternate navy blue uniform, did not unveil another full-time alternate until 2026, when they started wearing an orange alternate at home and a navy blue alternate on the road. This leaves the Yankees as the only MLB team without an official alternate uniform.
Starting in 2023, Major League teams are limited to a home, away and two alternate uniforms, as well as the City Connect uniform. As a result, a number of teams began to veer away from wearing gray uniforms on road games, something that was not seen since the "pullover" era of the 1970s–1980s.
In 2024, Nike and Fanatics received harsh criticism after modifying the template of each Major League uniform to the new Vapor Premier chassis. The most notable changes included lowering the MLB "batterman" logo below the neck piping (on some teams), shrinking the size of the letters on each player's name, and lack of customization options. While the intent was to make the uniform lighter and more breathable, players and fans disliked the newly-revamped uniforms for its poor quality. In 2025, Nike reversed some of these changes, including reverting to the former lettering sizes and fabric on gray uniforms, with more changes planned for 2026.
Teams and cities displaying
Typically, home uniforms feature the team's nickname, while away uniforms feature the name of the team's geographic designation. Currently, the Tampa Bay Rays, Los Angeles Angels, Philadelphia Phillies, St. Louis Cardinals, and Athletics are the only exceptions to this rule, although the Cardinals' aforementioned 2013 alternate placed "St. Louis" on their jerseys for the first time since 1932. In 2026, the Athletics introduced a gold alternate jersey with “Sacramento” across the chest to acknowledge their temporary home. These teams feature the club nickname on both the home and away uniforms (since 1900, in 169 seasons – including the Athletics' presence in the city from 1901 to 1954 – the full word "Philadelphia" has never appeared on a Major League jersey). The Milwaukee Brewers did not display their city name on their road gray jerseys from 2000 to 2019, and from 2000 to 2009, had an alternate blue jersey with "Brewers" on the front. They introduced a navy jersey with "Milwaukee" on the front in 2010, but kept the navy alternate with "Brewers" on the front; both navy jerseys were worn interchangeably at home and on the road for the next ten seasons.. The Brewers redesigned their uniforms for 2020, with "Milwaukee" on the front of the road grays for the first time since 1999.
From 1973 to 2008, the Baltimore Orioles were part of this group – the omission of the city's name being part of a largely successful effort to attract fans from the Washington, D.C. area – before returning "Baltimore" to the road jerseys in 2009, by which time the current Nationals franchise had begun playing in Washington, D.C. In 2014, the Los Angeles Dodgers and Chicago Cubs partially joined this group, carrying one road jersey with the city name and another with the team name, and wearing both interchangeably; in only the third game of the season, one player accidentally played the first inning in the "Chicago" jersey while the team wore "Cubs"; the Cubs dropped the alternate road jersey in 2016, leaving the "Chicago" version as the lone style.