LRT Line 1 (Metro Manila)

The Light Rail Transit Line 1, commonly referred to as LRT Line 1 or LRT-1, is a state-owned (through Light Rail Transit Authority (LRTA)) but privately operated (by Light Rail Manila Corporation (LRMC)) light rapid transit system line in Metro Manila, Philippines, and as part of the Manila Light Rail Transit System. Originally referred to as Metrorail and the Yellow Line, LRT Line 1 was reclassified to be the Green Line in 2012. It travels in a general north–south direction from Dr. Santos to Monumento, and then east–west from Monumento to Fernando Poe Jr. Currently, the line consists of 25 stations and runs on 26 kilometers (16 miles) of fully elevated route. Although it has the characteristics of light rail, such as with the type of rolling stock used, it is more akin to a rapid transit system owing to its total grade separation and high passenger throughput.

First envisioned in a 1977 study conducted by Freeman Fox and Associates which suggested a street-level railway in Manila, the government revised this recommendation to an elevated system. In 1980, President Ferdinand Marcos created the LRTA and construction of the line began the following year. With its partial opening in 1984 and completion the following year, it became the first rapid transit service in Southeast Asia. LRT Line 1 would become one of the busiest among Metro Manila's three rapid transit lines, as it currently serves roughly 323,000 passengers daily.

The line is integrated with the public transit system in Metro Manila, and passengers also take various forms of road-based public transport, such as buses and jeepneys, to and from a station to reach their intended destination. Although the line aimed to reduce traffic congestion and travel times in Metro Manila, the transportation system has only been partially successful due to the rising number of motor vehicles and rapid urbanization. Expanding the network's revenue line to accommodate more passengers, through extension projects, is set on resolving this problem.