Earlier this year, Legge joined Dale Coyne Racing in the #51 entry at the Indianapolis 500 where she completed just 22 laps after an engine failure.
After her career-best 231.627 mph lap and 231.070mph four-lap average in qualifying for last year’s Indianapolis 500, Legge lays claim to being the fastest woman in IndyCar.
Legge, who hails from the United Kingdom, will contest the forthcoming double-header on the bullring oval which takes place on July 14-15 (AEST).
“I’m thrilled to be behind the wheel of an IndyCar Series car at the Iowa doubleheader this weekend,” said Legge.
“We had a successful test there last week, and I’m really looking forward to seeing how the races unfold on the new surface.
“I’m grateful to Dale Coyne and Honda and so happy to be back in the #51.”
Dale Coyne Racing has had a rotating roster of drivers in the #51 car this season.
So far, six drivers have shared that entry, which is supported by Rick Ware Racing.
Daytona 24 winner Colin Braun was the first of those to pilot the car at St Petersburg before Nolan Siegel took the reigns at Long Beach.
Italian Luca Ghiotto, who spent five years across GP2 and Formula 2, has contested the most races of anyone in the #51 with four to his name.
IMSA driver Toby Sowery of the United Kingdom brought the team its best result with that car at the latest round in Mid-Ohio where he finished 13th.
Hunter McElrea could be next in line to drive the car at either Toronto or Portland following a test on Tuesday at Mid-Ohio.