The Renault team made the announcement on Tuesday after an online presentation of its new RS18 auto.
Also joining Hulkenberg and Sainz this season will be two new F2 drivers.
"They have become incredible team members who have built up strong relationships within Renault".
The French manufacturer finished sixth overall in last year's championship, up from ninth the previous season, and are aiming to close the gap further after significant investment in staff and facilities.
"Renault Sport Formula One Team's ambition is clearly to uphold the outstanding record of the past and the 2017 season has confirmed we are on the right track", said Jérôme Stoll, Renault Sport Racing President. I am convinced year three will take us one step closer to the long-term aim: "winning races and challenging for championships".
Speaking after images of the new auto were revealed, Renault Sport Racing President Jérôme Stoll said: "Renault Sport Formula One Team's ambition is clearly to uphold the outstanding record of the past and the 2017 season has confirmed we are on the right track".
"We have everything to be positive about this year", the Frenchman said.
"Our headline target is to show continued progression through results", said Abiteboul.
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While pace towards the end of the season helped the team to secure sixth place in the constructors' standings, power unit reliability gremlins increased the challenge for Renault and caused headaches for its customer teams Red Bull and Toro Rosso.
For 2018 we need to continue our upward trajectory.
Renault did not hold an official launch event but instead revealed their auto on Twitter in one of the most innovative unveils in memory.
The team derives its names from an abbreviation of Renault Sport and the year, a template adopted in 2016 with the R.S.16 when Renault re-assumed control of the Enstone-based team it controlled up through 2010.
Although the team was encouraged last season by the progress it made with the speed of its vehicle, as it often proved to be the fourth quickest team, it lost a number of good results through poor reliability.
He added: "Our first priority is for reliability and it's going to be even more hard as we have to get another quarter out of the engine life on top of the target for 2017".
Testing begins at Barcelona's Circuit de Catalunya on Monday, with the opening race in Australia on March 25.