The Baltimore Orioles' 2011 season was the 111th season in franchise history, the 58th in Baltimore, and the 20th at Oriole Park at Camden Yards. It also marked the last year of a streak of fourteen consecutive losing seasons dating back to 1998.
Offseason
The 2010–11 offseason has been notable for the Orioles, featuring a complete makeover of their infield, with only Brian Roberts expected to reprise his starting role. On December 6, 2010, the Orioles completed a trade with the Arizona Diamondbacks for third basemen Mark Reynolds, in exchange for relief pitchers David Hernandez and Kam Mickolio. The next day, the Orioles lost corner infielder, second baseman (40 games in 2010), and lone 2010 All-Star representative Ty Wigginton when he signed with the Colorado Rockies. On December 9, however, a deal was struck with the Minnesota Twins, acquiring shortstop J. J. Hardy, utility infielder Brendan Harris and cash in exchange for minor league pitchers Jim Hoey and Brett Jacobson. The following day, the Orioles re-signed former starting shortstop César Izturis, though now as a utility middle infielder. Finally, after weeks of rumor and speculation, concerning possible first base signings, the Orioles inked veteran free agent Derrek Lee on January 6, 2011.
The Orioles also worked to stabilize their bullpen whose depth had been weakened in trades to strengthen the infield. They began on December 13 by re-signing former starter and de facto closer Koji Uehara. The following day, the Orioles signed former Toronto Blue Jays reliever Jeremy Accardo. A month later on January 13, the Orioles signed former Blue Jays closer Kevin Gregg. Though still on the 40-man roster, the Orioles may have lost reliever Alfredo Simón, as he was charged with involuntary manslaughter in the Dominican Republic, following an accidental shooting death of his cousin during a New Year's celebration.
In addition to shoring up their bullpen, the Orioles signed Justin Duchscherer to a one-year deal.
On February 4, the Orioles signed free agent Vladimir Guerrero to solidify the offense. Guerrero had hit for 29 home runs and a .300 average in the 2010 season with the Texas Rangers. He also had a career average of .320 and 436 home runs prior to the 2011 season.
Regular season
The team started the season 4–0, the first time since the 1997 baseball season.
The Orioles eliminated the Boston Red Sox from the playoff on the final day of the season, the last of their five victories over the Red Sox in September. The Orioles were 15–13 in September, including two extra-inning wins over the division champion New York Yankees and another two wins against the AL wild card Tampa Bay Rays on September 13–14. They also stopped division champion Detroit Tigers's Justin Verlander attempt at 25 wins, beating the Tigers 6–5 while scoring five runs in Verlander's seven innings.
Roster
Season standings
Record vs. opponents
September 28 -- Game 162
Despite being in last place in the division (29 games out and with a 68–93 record), the Baltimore Orioles were a part of what is famously touted in Major League Baseball lore as the "Best Night Ever" in baseball with the AL and NL wild cards still tied and were up for grabs. The Orioles had gone 4-2 down the stretch vs. Boston with game 162 still left to play in Baltimore. The game was broadcast on ESPN as well as the MASN and NESN networks. The Orioles were aiming to play the role of spoiler and end the Red Sox season with help from the Tampa Bay Rays.
In the AL wild card race, The Boston Red Sox were suffering through a 7-19 stretch in which they had blown a nine-game lead on August 30 (which gave them more than a 99.7% chance of making the playoffs). This was a do-or-die game for the Red Sox, but felt they had a lot of momentum going into this game having beaten the Orioles, 8–7, the night before.