Ildefonso (Ildefonsus) is a Spanish given name, ultimately from Gothic Hildefuns, the name of 7th-century saint and archbishop Ildephonsus.
Other people with the given name include: Ildefonso Falcones (born 1959), Spanish author and lawyer Ildefonso Puigdendolas ((1876–1936), Spanish military officer Ildefonso Santos (1897–1984), Filipino educator and poet Ildefonso P. Santos Jr. (1929–2014), Filipino architect, son of the above
See also Alfonso, another name Alfonso (disambiguation)