詹姆斯·韦伯空间望远镜（James Webb Space Telescope，缩写JWST）是计划中的红外线太空望远镜，原计划于2011年发射升空。但因项目超支等原因，故发射改期为2018年。它是欧洲太空总署和美国宇航局的共用计划。这是哈勃太空望远镜和史匹哲太空望远镜的后继计划。它拥有一个分段的6.5-米 (21 英尺) 直径的主镜，并且放置于太阳─地球的第二拉格朗日点。不像哈勃空间望远镜那样围绕地球上空旋转，而是飘荡在地球背向太阳的后面150万公里的太空。一个大型遮阳板将保持它的镜片和四个科学仪器低于50 K（−220 °C；−370 °F）。

The James Webb Space Telescope (JWST), previously known as Next Generation Space Telescope (NGST), is a flagship-class space observatory under construction and scheduled to launch in October 2018. The JWST will offer unprecedented resolution and sensitivity from long-wavelength (orange-red) visible light, through near-infrared to the mid-infrared (0.6 to 27 micrometers), and is a successor instrument to the Hubble Space Telescope and the Spitzer Space Telescope. While Hubble has a 2.4-meter (7.9 ft) mirror, the JWST features a larger and segmented 6.5-meter (21 ft) diameter primary mirror and will be located near the Earth–Sun L₂ point. A large sunshield will keep its mirror and four science instruments below 50 K (−220 °C; −370 °F).