Lake Uluabat

Infobox lake
lake_name = Lake Uluabat
image_lake =
caption_lake =
image_bathymetry =
caption_bathymetry =
location =
coords = coord|40|10|N|28|35|E|type:waterbody_region:TR|display=inline,title
type =
inflow = Mustafakemalpaşa River
outflow = Ulubat stream
catchment =
basin_countries = Turkey
length =
width =
area = 135 to 160 km²
depth =
max-depth = 3 m
volume =
residence_time =
shore =
elevation =
islands = 8 (Halilbey Island)
cities = Gölyazı

Lake Uluabat (Uluabat Gölü), also called Ulubat Gölü or Apolyont Gölü, is the name of a freshwater lake in the vicinity of Bursa, Turkey. It is a large lake, covering an area of between 135 and 160 km², depending on the water level, but it is shallow, being only 3 m deep at its deepest point. The lake contains eight islands, and one other that is sometimes an island and at other times a peninsula. The largest island is known as Halilbey Island. In the southwest the lake is fed by the Mustafakemalpaşa River, which has formed a silty delta. Water leaves the lake by way of the Ulubat stream, flowing to the west, and reaches the Sea of Marmara via the Susurluk stream. The village at the shore of the lake called Gölyazı.

Most shores of the lake are covered in submerged plants, and it has the most extensive white water lily beds in Turkey. Ulubat Lake is one of the breeding areas for the endangered Pygmy Cormorant ("Phalacrocorax Pygmeus"). The latest DHKD (Society for the Protection of Nature Turkey) survey (June 1998) found 823 pairs of Pygmy Cormorants, 105 pairs of Night Heron, 109 pairs of Squacco Heron, and 48 pairs of Spoonbill breeding on Ulubat.

The alternative name Apolyont comes from the ancient Greek name "Apollonia", the name of an ancient city (Apollonia ad Rhyndacum) that was once situated on its banks, which had considerable importance since it was on the main trade routes. Modern residential areas by its shores are Mustafakemalpaşa (formerly called Kirmasti) and Karacabey. The area was famous for centuries for its silkworm cultivation, but this industry has died out, due to synthetic fabrics. The main industry today is fishing.