The 49-year-old is unlikely to take another job before the end of the season, with a Mercedes statement saying he will 'take a break from the sport in the coming months' before he picks his next role.
In that same statement, Elliott said: “It has been one of the great privileges of my career to be part of this Mercedes team. During my time, I have seen it grow from a group of people pulling together to win races, then a first championship, to winning a record eight consecutive constructors' championships – and I am proud to have made my contribution to that journey."
Elliott: Mercedes' last two seasons have been testing
He continued: “Although the last two seasons have not seen us winning races in the manner we aspire to, they have tested us in many other ways – and forced us to question our fundamental assumptions about how we deliver performance.
"During the past six months, I have enjoyed developing the technical strategy that we hope can provide the foundations of the team’s next cycle of success.
“I have decided that now is the right time to make my next step beyond Mercedes – first to pause and take stock, after 23 years of working flat-out in this sport, and then to find my next challenge. I would like to thank my team-mates for a fantastic 12 seasons together and wish them every success for the years to come.”