Mandaluyong, officially the City of Mandaluyong (Lungsod ng Mandaluyong), is a first class highly urbanized city in the National Capital Region of the Philippines. According to the 2020 census, it has a population of 425,758 people.
Located directly east of Manila, Mandaluyong was originally a barrio of Santa Ana de Sapa (now a district of Manila) called San Felipe Neri. It separated and became its own town in 1841, and later acquired the name Mandaluyong in 1931 during the American occupation. In 1994, it became the first municipality of Metro Manila to become a city since the metropolis' establishment in 1975.
At present, it is known for the Ortigas Center, a commercial and business center that it also shares with the city of Pasig. Notable institutions and establishments in the city include the Asian Development Bank, the headquarters of Banco de Oro and San Miguel Corporation and shopping malls like Shangri-La Plaza and SM Megamall.
The city is bordered by Manila to the west, San Juan to the north, Quezon City to the northeast, Pasig to the east, and Makati to the south. It is also the 6th-smallest city in the Philippines with a land area of , similar to Makati and Marikina.
There are different stories on the origin of the name Mandaluyong.
One tells of how the place was abundant with a kind of tree called luyong, now more commonly known as anahaw (Saribus rotundifolius), from which canes and furniture were made.
Another claims that the Spaniards named the place based on the report of a navigator named Acapulco, who saw the rolling hills frequently being lashed at by daluyong (“big waves from the sea”). This seems to confirm traditional pre-Hispanic stories that giant waves from the sea would meet the adjoining hills of the vast lowland, referred to as salpukan ng alon. Felix dela Huerta, a Franciscan historian, observed that the rolling topography of this land resembled giant waves of the sea.