SM Megamall was constructed in 1989 and opened its doors on June 28, 1991. It is the third SM Supermall ever built by Henry Sy Sr. after the SM City Sta. Mesa and SM City North EDSA. The mall is located in the Ortigas Center at the portion encompassed by Mandaluyong City. It stands along the main EDSA thoroughfare and is almost adjacent to the Ortigas MRT Station. The SM Megamall was the largest mall in the country for a 17-year period, but when the SM Mall of Asia was built in 2006, it was ranked third largest in the country by floor area at that time, measuring of total retail floor area and after SM City North EDSA. It also boasted the first ice skating rink as well as one of the first trade halls in the country. By 2010s, SM Megamall expanded with the addition of the Building C in 2011 and the Mega Fashion Hall in 2014, bringing the total retail floor area to. In 2018, SM partnered with Cal-Comp Technology Inc. for the provision of its New Era AI Robotic service robots stationed at SM Megamall by the first quarter of 2019.
Buildings
Main Mall
The mall has two main buildings. Building A features the 12 digital cinemas on the third floor, a foodcourt and Toy Kingdom on the lower ground floor and other anchor tenants. It also features Forever 21 located on the second level of Building A. Building B features The SM Store, Cyberzone on the fourth floor, The Mega Trade Hall on the fifth floor, and other anchor tenants. It has been expanded with the Mega Fashion Hall which opened in January 2014. The SM Supermarket is featured on both buildings. The bridgeway connecting the two main buildings of the mall contains several eateries.
Mega Atrium
The Mega Atrium is an addition to the existing two buildings. The Atrium, completed in 2008, bridges the gap between Buildings A and B. It features Chapel of the Eucharistic Lord, a 1,585 sqm chapel located on the fifth floor, as well as various shops and restaurants. It can also be rented out as an event venue.
Building C
Building C is a more recent addition to SM Megamall. Formerly Building A's open-parking facility, it is located near EDSA to the west of Building A and was opened on October 11, 2011. Office space is located on the upper levels of the carpark. It also houses an integrated bus terminal serving the north of Metro Manila including CAMANAVA, Quezon City and further to Bulacan and Rizal. The building also contains a transport terminal and the DFA CO NCR-East, the first passport office of the Department of Foreign Affairs in Metro Manila which opened in August 2012.
Mega Fashion Hall (Mega D)
The Mega Fashion Hall is the latest expansion of SM Megamall. Featuring a two-level basement parking and a five-level mall with of retail, it houses several global clothing retailers including the three-level H&M store and the three-level Uniqlo which extends to the two uppermost levels of Building B. Aside from clothing stores, the expansion includes dining establishments, houseware stores, service shops, and a Bingo area on the fifth level. The Mega Fashion Hall also houses an IMAX Digital theater, a 56-seat Director's Club Cinema with butler service, an Olympic-sized ice skating rink, an upscale food court, and a 14-lane bowling center.
Expansion
After the soft opening of the newly constructed Building C Carpark, the mall surpassed SM Mall of Asia by and became the second largest shopping mall in the country. With the opening of the Mega Fashion Hall, the current gross leasable area is, allowing the mall to reclaim the title of the largest mall in the Philippines. The addition of the Mega Fashion Hall building added 125 new retail stores, 90% of which are global brands and 10% of which are local retailers.
Office Tower
A 50-storey office tower, named The Mega Tower, will be built next to the Mega Fashion Hall formerly occupied as an open carpark. The S-shaped tower will be directly connected to the Mega Fashion Hall and will feature three levels of basement parking and multilevel parking. It will have a leasable area of. Arquitectonica is the firm responsible for the architectural design while Aurecon is the structural engineer for the building project.
Incidents and accidents
May 21, 2000: A bomb exploded inside a restroom at Cinema 6 of the mall's movie theater located on the third floor. One person was killed and dozens injured. Two of the victims sustained very serious injuries.
January 26, 2013: A holdup and shootout occurred when the Martilyo Gang, a local criminal group specializing in robbing stores by smashing and stealing valuables using hammers, robbed a jewelry store in the department store on the first floor.
May 5, 2013: An explosion briefly caused panic at the foodcourt at Building A, with at least one reported hurt in a stampede before shoppers were able to calm down after learning the sounds were not gunshots. A siomai steamer was short-circuited and caused people to file out at around 7:25 PM
June 29, 2018: A fire hit the SM Mega Tower under construction near SM Mega Fashion Hall at around 7:30 PM. It was declared "fire out" at around 6 hours later, at 1:30 AM on the next day. The Metropolitan Manila Development Authority had announced in a tweet at 8:16 PM on Thursday that the blaze had already reached the third alarm. This meant that up to nine fire trucks should be deployed.
