The Orioles made many significant roster moves prior to the 2010 season. The team parted ways with several contributors from the 2009 season including Aubrey Huff, and Melvin Mora who was the team's longest tenured player. Miguel Tejada returned to the team to replace Mora at third base and brought in Garrett Atkins to play first. The Orioles also looked to improve the pitching staff by trading for veteran Kevin Millwood from the Texas Rangers and signing free agent closer Michael Gonzalez.
Regular season
Despite some predictions that the Orioles would have one of their best seasons in years, the Orioles continued to struggle throughout the first half of the season. The Orioles 2010 season got off to a horrendous start the team going 2–16 to start the season, last in the league by some margin and the second-worst in franchise history. On April 12, the team set a club record for the lowest paid attendance in Camden Yards history as only 9,129 attended the game versus the Tampa Bay Rays. They would end the month of April 5–18. May would be only slightly better as the team posted a 10–18 record for the month. On June 4, 2010. the Orioles fired manager Dave Trembley after compiling a record of 187 wins and 283 losses since being promoted during the 2007 season. At the time they were on an 8 game losing streak and had the worst record in the league at 15-39. Trembley was replaced by third base coachJuan Samuel on an interim basis. The managerial change accomplished little as the team's struggles continued under Samuel. Despite sweeping a four-game series from the Texas Rangers in Texas to head into the All-Star break, the Orioles went 25–59 in the first half. The team went 7–19 in the month of July. On July 29, the Orioles hired Buck Showalter to be the team's full-time manager. He was introduced on August 2 and made his debut on August 3, by which time Samuel's record as manager was 17-34. Showalter chose to wear the number 26 in honor of his friend and former Orioles manager Johnny Oates. It was announced that Juan Samuel would not resume his role as third base coach and would instead take on a new role as a Dominican scout for the team. With Showalter in the dugout the Orioles went 17–11 in August, their first winning month all season and first winning August since 2004. However, on August 29, the Orioles became the first team to be mathematically eliminated from playoff contention for the MLB 2010 season. The Orioles finished out the season by going 17–13 in the months of September and October, making the team 34–23 under Showalter. This was the best record of any AL team over the same stretch of time, one commentator stating that "The Orioles had two different seasons. Before Buck and After Buck." 2010 also marked the first time since 2004 that the Orioles improved on their previous season's win total. Their final record for the 2010 season was 66–96.
Note: W = Wins; L = Losses; ERA = Earned run average; G = Games pitched; GS = Games started; SV = Saves; IP = Innings pitched; R = Runs allowed; ER = Earned runs allowed; BB = Walks allowed; K = Strikeouts