Vice-captain Trott has made over 25,000 runs for the Bears in all competitions since joining them in 2002.
The 35-year-old won 52 Test caps for England between 2009 and 2015, scoring 3,835 runs at an average of 44.08.
"He continues to be one of the leading batsmen in the professional game," sport director Ashley Giles said.
"He makes an outstanding contribution to Warwickshire as a batsman, vice-captain and mentor to the younger members of the squad.
"He's a proud Bear and ensuring that he remains at Edgbaston for at least the next two years is a huge boost to the club as we build towards the new domestic season."
Trott has helped Warwickshire win two County Championship titles, the T20 Blast, the ECB 40 and the One-Day Cup in his time with the county.
Former England batsman Jonathan Trott has extended his contract with Warwickshire until the end of the 2018 county season.