Castroneves is the latest pick for the Project 91 program, which gave NASCAR Cup Series starts to Kimi Raikkonen and Shane van Gisbergen across 2022 and 2023.
After a one-year hiatus, Project 91 will return with the IndyCar legend steering a Chevrolet Camaro.
Castroneves will look to join Mario Andretti and AJ Foyt as the only drivers to win the Indianapolis 500 and Daytona 500.
“Never in my wildest dreams did I think I would enter a NASCAR race and certainly not the Daytona 500 with a team like Trackhouse Racing,” said Castroneves.
“This is an opportunity that nobody in their right mind could ever turn down.
“I am so thankful to Wendy’s for allowing me to wear their uniform and drive their car, Justin Marks (Trachouse Racing owner) and everyone that made this happen.
“I wish the race were tomorrow.”
For all intents and purposes, the Brazilian is a stock car racing rookie having never competed in any NASCAR division.
The closest Castroneves has come to NASCAR is the International Race of Champions and the Superstar Racing Experience.
Castroneves will be part of the Trackhouse Racing fold that includes full-timers Daniel Suarez, Ross Chastain, and van Gisbergen.
The 49-year-old will have Darian Grubb as his crew chief for speed week.
“I know how much of a challenge this is going to be, but I also know the type of people and team Trackhouse Racing will bring to the effort,” said Castroneves.
“I can’t wait to get to the Trackhouse race shop in North Carolina to meet everyone and prepare for Daytona. There is so much I must learn and I’m ready to get started.”
Trackhouse Racing owner Justin Marks said Castroneves was a logical choice for the return of Project 91.
“Hélio is one of the greatest drivers of all time and exactly the type of driver we want to bring to NASCAR,” said Marks.
“I think race fans around the world will be excited to see Hélio in NASCAR’s most prestigious race. It also exposes our sport to a global audience and allows them to see just how great of a series we have in NASCAR.”
The Daytona 500 takes place on February 17 (AEDT). Qualifying gets underway on February 13 before the Duels on February 14.
The highest-finishing non-chartered team in each Duel race will secure a spot in the Daytona 500.