The 2015 D.C. United season was the club's twentieth season of existence, and their twentieth in Major League Soccer, the top tier of the American soccer pyramid. The club entered the season as the defending Eastern Conference regular season champions.

Outside of MLS regular season play, the club participated in the 2015 U.S. Open Cup, as well as the knockout stages of the 2014–15 CONCACAF Champions League and group stages of the 2015–16 CONCACAF Champions League.

Background

Pre-season

January D.C. United began the season in 2015, after a successful 2014 campaign, in which D.C. United went undefeated during the 2014-15 CONCACAF Champions League group play. The team, seeking to maintain its success, thought to keep much of the team the same. In the final month of 2014, the team traded its late-season 2014 acquisition, reserve fullback/midfielder Samuel Inkoom, along with back-up goalkeeper Joe Willis, to the Houston Dynamo, in exchange for the MLS rights to Andrew Driver, whose contract had not been renewed by Houston. The main purpose of the trade was to remove an international player, Inkoom, from the roster, so the team could protect all of the major 2014 players in the 2014 MLS Expansion Draft. In the expansion draft, the team did lose veteran reserve midfielder Lewis Neal along with Thomas McNamara, who had just been acquired by the team in the 2014 MLS Dispersal Draft that followed the dissolution of Chivas USA. The team added depth in the 2015 MLS SuperDraft, selecting a projected winger, Miguel Aguilar, along with a central midfielder from the nearby University of Maryland, Dan Metzger. Several days before the draft, the team also signed veteran Finnish international, Markus Halsti, from the Swedish side Malmö FF. With Malmö, Halsti had played defensive midfield in recent years, after having spent the early years in his career playing as a defender. On the day before the SuperDraft, the team also traded one of its unused international player roster slots to the Columbus Crew in exchange for forward Jairo Arrieta.

Ben Olsen, who was awarded league honors as the 2014 MLS Coach of the Year, continued to manage the side along with General Manager Dave Kasper. The team lost two 2014 assistant coaches, goalkeepers coach Preston Burpo and staff assistant Enzo Concina. Prior to the Superdraft, the team prepared to hire longtime MLS goalkeeper, former league All-Star and Maryland native Zach Thornton to replace Burpo. Several D.C. United players were invited to participate in a January training camp for the United States men's national soccer team, including Perry Kitchen and Steve Birnbaum. 2014 MLS Goalkeeper of the Year Bill Hamid had to decline because of a lingering shoulder injury.

The big offseason news for the team, however, did not involve players or the coaching staff. At the end of 2014, the team culminated years of searching for a site to construct a new stadium. The team's long efforts were rewarded in December 2014, with the passage of legislation by the D.C. City Council that committed the city to spend as much as $150 million to acquire and prepare the necessary land at Buzzard Point, which would be leased to the team for at least 30 years. The team was prepared to build a stadium on the site for another $150 million. The bill was signed into law by the outgoing Mayor Vincent C. Gray, in his final days in office. D.C. United hoped to move into its new 'soccer-specific' stadium for the 2017 season, and prepared to play the team's final 2 seasons in RFK Stadium.

February D.C. United acquired Michael Farfan with its MLS Allocation signing spot and soon after released Driver and Metzger from the team. The team travelled to Austin, Texas where the Austin Aztex hosted a friendly 4-team tournament, the ATX Pro Challenge. D.C. managed to win this tournament by beating the host team with a pair of early goals in the semifinals, and then beating runner-up FC Dallas in the finals. The team won a bronze armadillo trophy for their efforts.

After the tourney, David Estrada was released from the team and undrafted goalkeeper Travis Worra was signed to provide depth at the position after Willis' departure. The team travelled to Costa Rica to fight Alajuelense in the quarterfinals of the CCL. Bill Hamid struggled with a back issue and stayed home while backup Andrew Dykstra was given the starting job. Unfortunately, several errors by Dykstra and the defense led D.C. United to a horrendous 2–5 defeat.

March Despite a great effort to dig themselves out of a three-goal deficit, a lack of successful finishes and an accidental Own Goal by Chris Korb meant D.C. United would be knocked out of the CCL on a 4–6 aggregate score. The match was also notable for the referee handing out a combined nine yellow cards to both sides.

Regular season After the MLS and the MLS Players Union managed to sign a new CBA, the team successfully opened the 2015 MLS season with a 1–0 win at home against the Montreal Impact. Fabian Espindola, Eddie Johnson and Luis Silva were all unable to play in the match, heavily draining DC's offense. The newly added Jairo Arrieta started at forward alongside a healthy Chris Pontius and scored the first goal of the season for the team. Following a bye week, DC United traveled to New Jersey to fight the rival New York Red Bulls. Unfortunately, an anemic offense and poor marking by the DC backline led to a dispiriting 2-0 defeat.

DC returned home to fight the defending MLS Champions, the LA Galaxy, in RFK. Sophomore center back Steve Birnbaum landed awkwardly on his ankle and had to be taken off the field in the fifth minute of play as Kofi Opare got his first league cap in a DC United uniform. Just as it appeared the game would end in a scoreless draw, at the very last minute of the match, Nick DeLeon broke free down the right wing and sent in a cross to Pontius, who fought off his own defender to head the ball past the keeper for a 1–0 victory.

April A similar scenario would unfold in the very next match against Orlando City SC. Orlando had an advantage in ball possession and shots on goal, but Hamid's excellent saves would earn him another clean sheet. Silva, who finally returned from his preseason injury as a substitute, bent a direct free kick into the opposing net in stoppage time and secured a 1–0 victory for DC. When DC United returned home following the Orlando match, press reports emerged that Eddie Johnson's career was in jeopardy because of a heart defect. Although the team continued official radio silence on the issue, the Washington Post eventually reported that Johnson would no longer continue to be paid by the team. Outstanding issues remained to be negotiated before this would be officially confirmed. These issues included whether DC would be allowed to sign a replacement using the salary cap space budgeted to Johnson's contract.

On the pitch, things continued fairly brightly for the team, which finished the month atop both the Eastern Conference and overall MLS standings based on most points per game. Despite squandering second-half leads at home against both the New York Red Bulls and the Houston Dynamo, United did not lose in April. Against New York, DC, took a 2–0 lead on a pair of goals by Perry Kitchen. The Red Bulls came back to get a point, culminating the comeback as Lloyd Sam knocked in a rebound when Hamid could not control a Sacha Kljestan free kick. In the next match, against the Dynamo, United's Chris Rolfe scored on a free kick from almost the same spot that the Red Bulls took their game-tying free-kick in the previous match. Once again, though, the defense failed to prevent a late goal on a tap-in following a rebound allowed by the DC goalie, This time it was Andrew Dykstra who was in the net, unable to prevent the tying goal. After the successive disappointing home draws, DC United finished the month with a surprising win in Vancouver, a first ever for the franchise. The Whitecaps opened the scoring in that match with a goal on their first foray forward, but DC responded with a goal by Bobby Boswell to knot the score. Just before halftime, Fabian Espindola, drew a foul along with a second yellow card for Whitecaps player, Matias Laba. Espindola was making his MLS season debut after serving a 6-game suspension. Playing with a man-advantage, United took the lead in the second half on a goal by Chris Rolfe. Defending the lead was made more challenging when goalie Andrew Dykstra injured his ankle and had to be subbed off. Dykstra was playing because Bill Hamid was back in Washington, missing his second straight match, nursing a thigh injury. Rookie Travis Worra came on to make his MLS debut, manning the goal as United held on for a 2–1 win.

May The winning ways continued for United with three home games to start the month. In the first, United defeated the Columbus Crew 2–0, with two first half goals. The first came on a shot by Espindola that finished off a play that began with a 40-yard run by Rolfe, who got the assist on a perfectly weighted pass through the Crew defense. Espindola had the assist on the second goal with a corner kick to the far post when Sean Franklin volleyed for the goal. Back in goal for this game, Hamid earned yet another shutout. United's impressive home unbeaten streak continued a week later, with a 1–1 draw against Sporting Kansas City. A long pass from Perry Kitchen found Pontius, who chested the ball into the path of Jairo Arrieta, and Arrieta's shot found the back of the net. United gave away the lead about a minute later, just before halftime, as a cross by Sporting's Roger Espinoza found the foot of Dom Dwyer for the tying goal. Four nights later, United again defended Fortress RFK, against MLS debutantes, Orlando City SC. Missing star striker Espindola due to injury, United started slowly and Orlando capitalized as rookie Cyle Larin, the first pick in the 2015 MLS Superdraft, pounced on a loose ball in the box and beat goalie Bill Hamid. However, United was able to rally with two goals over the final 20 minutes to come away with a 2–1 win and regain the lead in the Supporters Shield race. A free kick by Taylor Kemp found the head of Opare, who was starting in place of the injured Birnbaum. Rolfe got the game-winner, stretching his leg out to get on the end of a cross by Arrieta, and tipping it in for the goal that sent the crowd into a frenzy.