Justin Wilson's number 25 Honda car will be driven by Oriol Servia in this weekend's IndyCar season finale at Sonoma Raceway.
Briton Wilson, the 37-year-old former F1 driver, died after he was struck by debris in last Sunday's Pocono IndyCar 500 and crashed into a wall.
Servia said: "I have known and raced Justin for more than 10 years.
"I am honoured and emotional with the opportunity of driving his car this weekend."
Wilson's younger brother Stefan supported the decision of Andretti Autosport to run the car.
"As a family, we cannot imagine a better person to race in Justin's honour than Oriol," he said.
"His path and Justin's crossed in many different ways through the years. As a competitor, and also as a person, he carries Justin's spirit well, and we know that Justin would approve."
Team owner Michael Andretti added: "Justin was a true racer and advocate to our sport.
"We will have Justin and his family in our hearts this weekend as we honour him in the way he would want us to, by doing what he loved - racing."
Honda say a contribution of $50 (£32) for every lap completed by each of their 13 cars competing at the Californian circuit this weekend will be made to the Wilson Children's Fund.
The fund was established this week to benefit the two daughters of Justin Wilson and his wife Julia.