Atanasio de la Cruz Aguirre (2 June 1801 – 28 September 1875) was acting President of Uruguay from 1864 to 1865.

On March 1, 1864, Bernardo Berro stepped down from the Presidency.

During the Paraguayan War, Francisco Solano López had sought to send an army to aid Aguirre against Venancio Flores, who was supported by Brazilian troops.

With Montevideo under siege, Atanasio de la Cruz Aguirre stepped down from the Presidency in favour of Senator Tomás Villalba, who soon made peace with the Colorado Party besiegers, allied with Brazil.

[2] This transition of power marked the coming to Presidential office of heads of state of the Colorado Party, which then remained in office for nearly a century.