The announcement ends speculation about Lawson's future with the team.
"I have no doubt that this is the best driver line-up for us, bringing a strong combination of experience and ambition," said team principal Alan Permane in a statement.
Lawson has scored 75 of Racing Bulls' 114 points in 20 races so far this season, with the team currently fifth overall. His place was uncertain, however, with 19-year-old Bulgarian junior driver Nikola Tsolov also linked to the seat.