Ten Doeschate told ESPNcricinfo he would "take stock" before committing to a new contract at the club after leading them to a second Championship title in three years, saying he was "deeply aware there's a time to move on."
But after his team-mate of 16 years Bopara left the club to join Sussex on Wednesday, ten Doeschate confirmed that he would spend the 2020 season at Essex.
Ten Doeschate said: "I'm really pleased to extend my contract at the club and my affinity for Essex and the players just grows stronger and stronger.
"We had an amazing season in 2019, but we're constantly striving to improve and we want to build on our success.
"I'm excited about the challenges and battles we'll face in 2020, and I'm looking forward to giving my all in what will hopefully another successful year."
Ten Doeschate captained the club across formats from 2016 to 2018, but relinquished the T20 captaincy to Simon Harmer this year. He has represented the club 477 times in all formats, scoring 27 hundreds and taking more than 300 wickets in the process.
He is currently in the UAE, where he will hope to play a key role in leading Netherlands through the T20 World Cup qualifier.
Anthony McGrath, Essex's head coach, said: "Ryan is a huge player for us, both on the field and in the dressing room, so we are all delighted that he will be staying for at least another season.
"He's a natural leader and has led this side to some fantastic achievements over recent years, and hopefully with any luck, there will be more to come."