While the 27-year-old German is yet to confirm his plans for 2015, it is believed Vettel is heading to Ferrari.
Toro Rosso driver Daniil Kvyat will partner Australian Daniel Ricciardo at Red Bull next season.
An official Red Bull statement on Saturday read: "Sebastian Vettel has advised us that he will be leaving Red Bull at the end of the 2014 season.
"We want to warmly thank Sebastian for the incredible role he has played at Red Bull for the last six years."
Vettel, who is racing at the Japanese Grand Prix this weekend, confirmed his departure without revealing his next move.
"After 15 very enjoyable and successful years with Red Bull, I have decided to leave Red Bull at the end of this year," he wrote on his website.
"Of course it is a big step and hard to make such a decision. The chance to drive in F1, the first win with Scuderia Toro Rosso, the four championship wins with Infiniti Red Bull Racing and many other great memories have bound Red Bull and myself together into a kind of family. No one can take these times away from us.
"Now I have decided to take the next step in my career but first I would like to express once again big thanks to Dietrich Mateschitz, Dr Helmut Marko, Christian Horner, the whole Red Bull family, Infiniti Red Bull Racing and Scuderia Toro Rosso.
"I would like to thank everybody within Red Bull for their confidence in me, trust and great support over the last years.
"About my future plans, there will be an announcement very soon."
Ferrari driver Fernando Alonso has been linked with a move to McLaren, one which would open up a seat for Vettel alongside Finn Kimi Raikkonen.
Kvyat, meanwhile, expressed his pride at being named as Vettel's replacement at Red Bull.
" I am very pleased about it, very honoured and happy and I have to thank Red Bull for this great opportunity," Kvyat told Sky Sports F1.