(written from a Production point of view)
Channel 4 was one of the UK broadcasters of Star Trek. The channel held the rights to show reruns of Star Trek: Enterprise, after outbidding the BBC in 2002 (Sky One held the first-run rights). It first aired on Wednesdays at 6 pm, before moving to Sunday afternoon upon the commencement of the third season. It aired as part of the T4 programming strand, often as a double bill.
In October 2019, Channel 4 announced that they had bought the linear rights to broadcast Star Trek: Discovery free-to-air on their E4 channel, beginning on 15th December 2019 and continuing weekly. 
Channel 4 also owns Film4.