Space: 1999 - watch online: streaming, buy or rent
Currently you are able to watch "Space: 1999" streaming on Amazon Prime Video, fuboTV, Peacock Premium, Amazon Prime Video with Ads, Peacock Premium Plus, Shout! Factory Amazon Channel, Disney Plus or for free with ads on The Roku Channel, Pluto TV, Amazon Prime Video Free with Ads. It is also possible to buy "Space: 1999" as download on Amazon Video.
Besides streaming, you can also buy the series on DVD from GRUV and on Blu-ray from Amazon DVD / Blu-ray.
You can also stream the title for free on Plex Player.
