Laguna de Bay, also known as Laguna Lake and alternatively spelled "Laguna de Bae", is the largest lake in the Philippines. It is located southeast of Metro Manila, between the provinces of Laguna to the south and Rizal to the north. A freshwater lake, it has a surface area of 911–949 km2, with an average depth of about 2.8 meters and an elevation of about one meter above sea level. The lake is shaped like a crow's foot, with two peninsulas jutting out from the northern shore and filling the large volcanic Laguna Caldera. In the middle of the lake is the large island of Talim.

Bay, officially the Municipality of Bay, and colloquially known as Bae, is a 2nd class municipality in the province of Laguna, Philippines. According to the 2020 census, it has a population of 67,182 people.