Ildefonso (disambiguation)
- Alfonso
- Alfonso (disambiguation)
- Alfredo Ildefonso Schuster
- Church of Saint Ildefonso
- First Treaty of San Ildefonso
- Gothic name
- Ildefons Cerdà
- Ildefonso Falcones
- Ildefonso Islands
- Ildefonso Lima
- Ildefonso P. Santos Jr.
- Ildefonso Puigdendolas
- Ildefonso Santos
- Ildephonsus of Toledo
- Konstanty Ildefons Gałczyński
- La Granja (palace)
- Regina Marie Roche
- San Ildefonso
- San Ildefonso (disambiguation)
- San Ildefonso Ixtahuacán
- San Ildefonso Peninsula
- San Ildefonso Pueblo, New Mexico
- San Ildefonso, Bulacan
- San Ildefonso, Ilocos Sur
- San Ildefonso, San Vicente
- Santo Ildefonso
- Second Treaty of San Ildefonso
- Third Treaty of San Ildefonso