List of largest optical reflecting telescopes

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The following is a list of the largest optical reflecting telescopes sorted by mirror diameter. Note that two of the first three are not yet operational. This list does not currently include telescopes that are still in the conceptual/proposed stage, such as the Overwhelmingly Large Telescope or the European Extremely Large Telescope, or ones still in the early stages of manufacturing such as the Giant Magellan Telescope.

Name	Diameter	Mirror type	Nationality of Sponsors	Site	Built
Large Binocular Telescope (LBT)	2x8.4 = 11.8 m	2x single	USA, Italy, Germany	Mount Graham International Observatory, Arizona	2007
Southern African Large Telescope (SALT)	11.0 m	Mosaic	South Africa, USA, UK, Germany, Poland, New Zealand	South African Astronomical Observatory, South Africa	2005
Gran Telescopio Canarias (GTC)	10.4 m	Mosaic	Spain, Mexico, USA	Roque de los Muchachos Observatory, Canary Islands	2006
Keck 1	10 m	Mosaic	USA	Mauna Kea Observatory, Hawaii	1993
Keck 2	10 m	Mosaic	USA	Mauna Kea Observatory, Hawaii	1996
Hobby-Eberly Telescope (HET)	9.2 m	Mosaic	USA, Germany	McDonald Observatory, Texas	1997
Subaru (NLT)	8.3 m	Single	Japan	Mauna Kea Observatory, Hawaii	1999
VLT 1 (Antu)	8.2 m	Single	ESO Countries (European + Chile)	Paranal Observatory, Chile	1998
VLT 2 (Kueyen)	8.2 m	Single	ESO Countries (European + Chile)	Paranal Observatory, Chile	1999
VLT 3 (Melipal)	8.2 m	Single	ESO Countries (European + Chile)	Paranal Observatory, Chile	2000
VLT 4 (Yepun)	8.2 m	Single	ESO Countries (European + Chile)	Paranal Observatory, Chile	2001
Gemini North	8.1 m	Single	USA, UK, Canada, Chile, Australia, Argentina, Brazil	Mauna Kea Observatory, Hawaii	1999
Gemini South	8.1 m	Single	USA, UK, Canada, Chile, Australia, Argentina, Brazil	Cerro Pachón, Chile	2001
Multiple/Magnum Mirror Telescope (MMT)	6.5 m	Single	USA	Fred Lawrence Whipple Observatory, Arizona	1987 2002
Magellan 1 (Walter Baade)	6.5 m	Single	USA	Las Campanas Observatory, Chile	2000
Magellan 2 (Landon Clay)	6.5 m	Single	USA	Las Campanas Observatory, Chile	2002
BTA-6	6 m	Single	Russia	Zelenchukskaya, Caucasus	1976
Large Zenith Telescope (LZT)	6 m	Single	Canada, France	Maple Ridge, British Columbia	2003
Hale Telescope	5 m	Single	USA	Palomar Observatory, California	1948
William Herschel Telescope	4.2 m	Single	UK, Netherlands, Spain	Roque de los Muchachos Observatory, Canary Islands	1987
SOAR	4.2 m	Single	USA, Brazil	Cerro Pachón, Chile	2002

This table does not include all the largest mirrors manufactured; the Steward Observatory Mirror Lab produced the 6.5-metre f/1.25 LOTIS collimator used by Lockheed Martin for vacuum optical testing of other telescopes.