Lotus chairman Gerard Lopez says his team will pay tribute to the victims of Wednesday's railway accident, which happened in the Galician region of Spain.
At least 80 people were killed when the train left the rails near the Spanish town of Santiago de Compostela.
As a mark of respect, the Galician flag will appear on both E21s in Hungary this weekend.
"Following the tragic accident on Wednesday 24th July 2013 involving the passenger train in Galicia, I and all within Lotus F1 Team would like to extend our sincere condolences to the family and friends of those affected and involved," said Lopez.
"As a Galician, I will provide all the help and support possible to those affected by this disaster, which has taken place in an area of the country I know and love so well. As an expression of support, I would like to reach out to those involved and show my unity to the region.
"Furthermore, as a mark of respect and display of moral support, Lotus F1 Team will drive with the Galician flag on the rear wing end plates of both E21 Formula 1 cars throughout the weekend of the Hungarian Grand Prix."
Spanish drivers Fernando Alonso and Pedro de La Rosa also gave their support to those affected by the accident.