Guillermo is an established boys' name that peaked in 1998 and has grown less common since.
Guillermo is predominantly a boy name. In 2025 it ranked #902 for boy births in the United States (and #1,849 across all names), given to 264 babies — 270 including U.S. territories. Guillermo first appears in 1885 and peaked in 1998 (693 births).
| Year | U.S. births | U.S. + territories | ♀ Rank | ♂ Rank |
|---|---|---|---|---|
| 2025 | 264 | 270 | — | #902 |
| 2024 | 299 | 308 | — | #831 |
| 2023 | 294 | 294 | — | #833 |
| 2022 | 287 | 292 | — | #850 |
| 2021 | 299 | 304 | — | #812 |
| 2020 | 275 | 281 | — | #832 |
| 2019 | 320 | 328 | — | #747 |
| 2018 | 314 | 324 | — | #752 |
| 2017 | 289 | 297 | — | #795 |
| 2016 | 322 | 332 | — | #755 |
| 2015 | 389 | 399 | — | #661 |
| 2014 | 376 | 391 | — | #676 |
| 2013 | 348 | 368 | — | #690 |
| 2012 | 392 | 405 | — | #619 |
| 2011 | 408 | 422 | — | #604 |
| 2010 | 457 | 472 | — | #553 |
| 2009 | 534 | 554 | — | #507 |
| 2008 | 583 | 601 | — | #476 |
| 2007 | 610 | 640 | — | #454 |
| 2006 | 626 | 651 | #18,117 | #439 |
| 2005 | 616 | 644 | — | #434 |
| 2004 | 639 | 667 | — | #406 |
| 2003 | 595 | 629 | — | #428 |
| 2002 | 626 | 650 | — | #405 |
| 2001 | 620 | 658 | — | #402 |
| 2000 | 651 | 691 | — | #392 |
| 1999 | 665 | 698 | — | #387 |
| 1998 | 693 | 747 | — | #369 |
| 1997 | 632 | — | — | #382 |
| 1996 | 692 | — | — | #352 |
| 1995 | 629 | — | #12,302 | #380 |
| 1994 | 681 | — | #12,319 | #357 |
| 1993 | 661 | — | #10,983 | #360 |
| 1992 | 666 | — | #10,871 | #361 |
| 1991 | 590 | — | #9,638 | #389 |
| 1990 | 587 | — | — | #395 |
| 1989 | 532 | — | — | #404 |
| 1988 | 516 | — | #12,460 | #386 |
| 1987 | 388 | — | — | #451 |
| 1986 | 405 | — | — | #430 |
| 1985 | 437 | — | #11,243 | #409 |
| 1984 | 412 | — | — | #404 |
| 1983 | 423 | — | — | #394 |
| 1982 | 442 | — | #11,064 | #386 |
| 1981 | 433 | — | #10,952 | #392 |
| 1980 | 400 | — | #10,921 | #409 |
| 1979 | 394 | — | — | #400 |
| 1978 | 322 | — | — | #442 |
| 1977 | 351 | — | — | #422 |
| 1976 | 360 | — | — | #411 |
| 1975 | 354 | — | #9,558 | #416 |
| 1974 | 349 | — | — | #418 |
| 1973 | 347 | — | — | #419 |
| 1972 | 281 | — | — | #469 |
| 1971 | 314 | — | — | #461 |
| 1970 | 290 | — | — | #472 |
| 1969 | 244 | — | — | #494 |
| 1968 | 292 | — | — | #450 |
| 1967 | 242 | — | — | #484 |
| 1966 | 199 | — | #6,918 | #550 |
| 1965 | 203 | — | — | #539 |
| 1964 | 192 | — | — | #571 |
| 1963 | 193 | — | — | #567 |
| 1962 | 185 | — | — | #576 |
| 1961 | 171 | — | — | #607 |
| 1960 | 191 | — | — | #565 |
| 1959 | 184 | — | — | #580 |
| 1958 | 162 | — | — | #603 |
| 1957 | 158 | — | — | #612 |
| 1956 | 172 | — | — | #581 |
| 1955 | 150 | — | — | #604 |
| 1954 | 149 | — | — | #608 |
| 1953 | 126 | — | — | #638 |
| 1952 | 134 | — | — | #610 |
| 1951 | 133 | — | — | #611 |
| 1950 | 127 | — | — | #608 |
| 1949 | 137 | — | — | #577 |
| 1948 | 136 | — | — | #574 |
| 1947 | 114 | — | — | #646 |
| 1946 | 93 | — | — | #671 |
| 1945 | 94 | — | — | #626 |
| 1944 | 77 | — | — | #708 |
| 1943 | 79 | — | — | #726 |
| 1942 | 53 | — | — | #914 |
| 1941 | 89 | — | — | #646 |
| 1940 | 71 | — | — | #726 |
| 1939 | 63 | — | — | #765 |
| 1938 | 70 | — | — | #731 |
| 1937 | 67 | — | — | #746 |
| 1936 | 79 | — | — | #663 |
| 1935 | 72 | — | — | #720 |
| 1934 | 86 | — | — | #651 |
| 1933 | 74 | — | — | #699 |
| 1932 | 71 | — | — | #742 |
| 1931 | 100 | — | — | #586 |
| 1930 | 101 | — | — | #611 |
| 1929 | 94 | — | — | #630 |
| 1928 | 87 | — | — | #677 |
| 1927 | 100 | — | — | #632 |
| 1926 | 107 | — | — | #606 |
| 1925 | 88 | — | — | #688 |
| 1924 | 87 | — | — | #708 |
| 1923 | 89 | — | — | #684 |
| 1922 | 57 | — | — | #924 |
| 1921 | 44 | — | — | #1,060 |
| 1920 | 68 | — | — | #813 |
| 1919 | 43 | — | — | #1,041 |
| 1918 | 34 | — | — | #1,202 |
| 1917 | 40 | — | — | #1,049 |
| 1916 | 20 | — | — | #1,614 |
| 1915 | 33 | — | — | #1,132 |
| 1914 | 26 | — | — | #1,143 |
| 1913 | 16 | — | — | #1,337 |
| 1912 | 18 | — | — | #1,115 |
| 1911 | 10 | — | — | #1,147 |
| 1910 | 13 | — | — | #895 |
| 1909 | 5 | — | — | #1,554 |
| 1908 | 7 | — | — | #1,149 |
| 1907 | 6 | — | — | #1,257 |
| 1905 | 10 | — | — | #812 |
| 1904 | 10 | — | — | #780 |
| 1900 | 6 | — | — | #1,225 |
| 1897 | 5 | — | — | #1,132 |
| 1892 | 8 | — | — | #825 |
| 1885 | 5 | — | — | #1,002 |