What was originally known during construction as Crossroads Arena opened September 21, 1996, replacing the Buffalo Memorial Auditorium. The construction cost was $127.5 million, (approximately $195 million in 2016 dollars).
Naming rights were sold to Marine Midland Bank, part of the HSBC banking group in 1996, and the building was renamed Marine Midland Arena before the first game had been played. The bank bought the naming rights for 30 years then to expire in 2026. In 1999, as part of HSBC's worldwide corporate rebranding, the arena's name was changed to HSBC Arena, with the official renaming taking place on March 17, 2000. This name change coincided with the playing of the first college basketball tournament game in the arena's history. The press box in the arena is named after former Sabres broadcaster and Hockey Hall of Fame member Ted Darling. In 2011, Buffalo based First Niagara Financial Group reached an agreement to purchase HSBC Bank's upstate New York and Connecticut branch network. While naming rights to HSBC Arena were not included in the sale, First Niagara, HSBC, the Buffalo Sabres and other parties reached an agreement to establish a new naming rights deal with First Niagara. The name of the arena became First Niagara Center' that summer, with the official renaming taking place that fall. First Niagara bought the naming rights for 15 years, approximately the remainder of the time that was left on HSBC's naming rights deal with the arena. KeyCorp announced its plans to purchase First Niagara—and thus also the naming rights to the arena—on October 30, 2015. Although exterior signage was installed during the week of August 11, 2016, the renamed KeyBank Center became official on September 19, 2016.
On November 16, 1996, the arena's first JumboTron, an eight-sided scoreboard made by Daktronics with Sony video screens, fell to the ice while it was being remotely moved. This was minutes after a few players ended practice and hours before a game between the Sabres and Boston Bruins. Nobody was injured, but the game was postponed. The scoreboard was replaced later that season. In time for the Buffalo Sabres' 2007–2008 season, a new high-definition scoreboard manufactured by Daktronics was installed. In addition the four main speaker racks were removed and replaced and two additional speaker racks were added. The new scoreboard features four large high-definition video screens, surrounded by two 360-degree LED ribbon boards. The bottom of the board features large Buffalo Sabres logos with giant sabres crossed behind them. The handles of the sabres are lit with blue LEDs. The Sabres logos shoot smoke out of the Buffalo's nostrils every time a Sabres goal is scored or when the Sabres win at home.
The first update to the arena took place after the conclusion of the 1998-1999 hockey season. 95 seats were added behind the last row of the 300 level, raising the arena's hockey and lacrosse capacity from 18,595 to 18,690.
The second update to the arena took place in 2002-2003, when the Sabres replaced matrix board on the face of the second bowl with a LED ribbon. The original seamless glass boards were also removed, and replaced with boards with clear plastic stanchions, which gave when players were hit into them.
The third update to KeyBank Center took place for the 2007–2008 season. Two illuminated Sabres logos were added in the upper level of the pavilion on both sides of the Sports Headlines bar. Also, new LED ribbon boards were installed in the arena seating bowl in conjunction with the new HD scoreboard. Later in 2008, a mural was installed in the lower pavilion near the main entrance, containing pictures from the 2008 NHL Winter Classic held at Ralph Wilson Stadium, now known as New Era Field, in nearby Orchard Park, New York.
The fourth update took place during the summer and early fall of 2011. The major renovation included the demolition and installation of brand new locker rooms, decor and concession updates as well as fan enhancements. This $6 million locker room project led by Cannon Design of Grand Island saw an expansion from 8,000 to 15,220 square feet (743 to 1,414 m2) in size. The new Sabres locker room is designed as a circular room, complete with illuminated team logos on the floor and ceiling. Additional new facilities include a state of the art fitness center, new coaching offices, film rooms where players and coaches can watch previous games, and a players lounge with a kitchen and team chef. Also, the new Sabres locker room features a Wall of Fame featuring team history, the names and numbers of retired team jerseys. Limestones that were salvaged from the former Buffalo Memorial Auditorium are surrounded by glass, which features the names of all team players throughout franchise existence. Visiting team locker rooms were also expanded from 3,230 to 3,511 square feet (300.1 to 326.2 m2). Finally, a new post-game interview room was also built. In addition to the new locker rooms and training facilities, the public spaces within the arena were also upgraded.
Also as part of the update, the arena took on the Sabres Blue and Gold color scheme inside the arena bowl. It replaced the red color used on the team logo from 1996–2006. The previous Sabres logo (used from 2006–2010) was removed from the scoreboard and replaced with the current logo. All of the original television sets were replaced with new High Definition televisions. New food choices were added as part of the upgraded concessions. Signage was replaced or upgraded where needed. Restrooms saw cup holders and HD televisions added for fan convenience. Also, new chimes were added, which sound two minutes prior to the opening faceoff each period. This lets fans know to head towards the seating areas. Finally, the Sports Headlines bar has now been replaced by the Labatt Blue Zone.
The ice rink itself also saw a multimillion-dollar upgrade with adding a new dehumidifier system and cooling tower. All of the Zamboni machines were replaced and upgraded to feature laser beam leveling. These upgrades improve the quality of the ice surface. Outside, a new LED ribbon board was added to the entrance pavilion which can display upcoming events, scores, and team information, though it was subsequently removed to make way for the construction of a new pedestrian bridge to the adjacent HarborCenter complex in 2014.
The fifth update features the creation of the Tops Markets Alumni Plaza. In July 2012, the space located between the arena's entrance pavilion and the parking ramp saw the concrete bridge columns covered with brick. All of the team members that the Buffalo Sabres have had throughout existence are now featured on plaques that are mounted to the bricks. In addition, fans of the Sabres are able to purchase custom plaques that will be featured alongside the team members. Alumni Plaza's centerpiece is a 10' high bronze statue of The French Connection. These renovations were completed in October 2012.
The sixth update included multiple changes, including modifying the entrance pavilion due to the HarborCenter construction. That building is attached to the arena by an elevated walkway. HarborCenter is a mid-rise building with 2 hockey rinks, a Marriott hotel, retail space, IMPACT Training facility, restaurants including 716 Food and Sport and flagship Tim Hortons and a parking garage. Construction began in early 2013, while the restaurants and rinks opened in late October 2014. The elevated walkway connecting the KeyBank Center and HarborCenter buildings was completed and opened in early 2015, while the Marriott hotel opened in the summer of 2015. Also, after the 2011-12 Buffalo Sabres season, the Sabres added 380 seats, mainly as an additional row in the 200 level, to raise the arena's capacity to 19,070. This number is symbolic of the team's founding in 1970. In 2013, the Buffalo Sabres announced that all 80 luxury suites would be renovated over a 3-year period. All suites will now feature the Sabres Blue and Gold color scheme, 50" televisions, new carpeting, new furniture and gathering islands. Construction began on this project in July 2013.
The seventh update took place during the summer of 2016 on the exterior due to the renaming from First Niagara Center to KeyBank Center. The entrance canopies that featured hockey images were replaced. New exterior signage was installed during the week of August 11, 2016 and KeyBank debuted the rebranded arena on September 19, 2016. Also, a new LED lighting system was installed by Ephesus. This allows the arena to provide better lighting while significantly reducing the number of light fixtures needed and reducing energy consumption.
In addition to the Buffalo Sabres, KeyBank Center is home to the Buffalo Bandits of the National Lacrosse League. The arena was the home of the Buffalo Destroyers of the Arena Football League, the Buffalo Blizzard of the National Professional Soccer League II and the Buffalo Wings of Roller Hockey International during each team's brief existence. During the 2012 NHL lockout, the arena has hosted several Rochester Americans games and continues to host occasional Americans games at the arena. The Toronto Raptors played a preseason game vs. the Miami Heat at the KeyBank Center in Buffalo in 1996 in front of 12,000 people. The arena also is used regularly for college basketball games and hosts concerts. It has been home to the NCAA (2000, 2004, 2007, 2010, 2014, 2017) and MAAC (1997, 1999, 2001, 2005) men's basketball tournaments. In 2003, the arena hosted the Frozen Four NCAA Ice Hockey tournament. The arena was also host to a house party for the 2008 NHL Winter Classic. Festivities included the Buffalo Sabres Alumni Hockey Team playing in pre-game action, followed by the Winter Classic shown on the scoreboard. From December 2010 to January 2011, the arena hosted the IIHF World Junior Championship tournament. In October 2014, the arena hosted its first Ontario Hockey League contest, a neutral-site game between the Erie Otters (who counted among its players marquee prospect Connor McDavid) and the Niagara IceDogs. The arena hosted the 1998 NHL Entry Draft and the 2016 NHL Entry Draft. The arena has hosted many WWE events including WWE Fully Loaded 1999, The Great American Bash 2005, Armageddon (2008), Night of Champions (2011) and Battleground (2013). Since 2004, a number of Raw and SmackDown tapings have occurred here, most recently a live episode of Raw on November 14, 2016.
The arena is also a regular stop for major concert tours and is the largest regular concert venue in Buffalo proper (it is one of two regular stops in Western New York for concert tours, the other being the performing arts center at Darien Lake). In March 2015, the arena hosted country music legend Garth Brooks for a 4-night, 6 show, sold out string of shows, bringing over 100,000 people to Downtown Buffalo. He also had his wife, Trisha Yearwood, along for the shows. It is a regular stop on Trans-Siberian Orchestra's annual circuit. For 2016, the area will be host to multiple concerts including Kanye West, Blake Shelton, Rihanna, Carrie Underwood, Justin Bieber, Demi Lovato with Nick Jonas and Maroon 5 and AC/DC so far. In 2017, Ariana Grande will perform at the arena, in support for her Dangerous Woman Tour, on February 21. Country music power couple Tim McGraw and Faith Hill will be bringing their 2017 Soul2Soul World Tour to Key Bank Center on October 27, 2017. This tour makes the first time the couple has toured in over 10 years (Soul2Soul II Tour). A live recording of Bruce Springsteen and the E Street Band's performance at the arena in 2009 titled HSBC Arena, Buffalo, NY, 11/22/09 was released on December 24, 2016.
In its ice hockey/indoor lacrosse configuration, the KeyBank Center can seat 19,070 spectators. In the event that the arena is being used for a concert, basketball game or other event that does not require the entire 200×85 surface, the total number can increase, accounting for seats or standing space on the arena's floor. Both sporting events and concerts at the arena are served by the Special Events station of the Buffalo Metro Rail.