Explore the Family Name Ildefonso

The meaning of Ildefonso

Portuguese and Spanish: from the personal name Ildefonso, from a Visigothic name Latinized as Ildefonsus, composed of the elements hathu ‘war’ + funs ‘ready’.

Dictionary of American Family Names, 2nd edition, © Oxford University Press, 2022.

How common is the last name Ildefonso in the United States?

Based on the Decennial U.S. Census, the surname Ildefonso has become more popular in the United States over the past decade. In 2000, it ranked 43,058 in popularity but jumped to 35,812 by 2010, reflecting a growth of 16.83 percent. The number of people with the surname also increased during this period, rising from 473 to 627, an increase of 32.56 percent. The proportion of individuals named Ildefonso per 100,000 people also grew by 16.67 percent.

	2000	2010	Change
Rank	#43,058	#35,812	16.83%
Count	473	627	32.56%
Proportion per 100k	0.18	0.21	16.67%

Race and Ethnicity of people with the last name Ildefonso

The ethnic identity associated with the surname Ildefonso also saw some changes between 2000 and 2010, according to data from the Decennial U.S. Census. While the majority of individuals with this surname identified as Hispanic (70.81 percent in 2010, up slightly from 69.56 percent in 2000), there were decreases in those identifying as Asian/Pacific Islander and White. The percentage of Ildefonsos identifying as Asian/Pacific Islander fell by 6.55 percent, and those identifying as White dropped by 3.75 percent. However, there was a noticeable increase in those reporting two or more races, from 1.06 percent in 2000 to 1.44 percent in 2010. No Ildefonsos identified as Black or American Indian and Alaskan Native in either census year.

	2000	2010	Change
Hispanic	69.56%	70.81%	1.8%
Asian/Pacific Islander	23.04%	21.53%	-6.55%
White	6.13%	5.9%	-3.75%
Two or More Races	1.06%	1.44%	35.85%
Black	0%	0%	0%
American Indian and Alaskan Native	0%	0%	0%