The baby name Rex appears in baby name data for the United States from 1910 to 2024. It was most popular in 1955 with 1,981 babies given the name.
Over the period shown, Rex has stayed at a similar level of popularity.
| Year | Count |
|---|---|
| 1910 | 18 |
| 1911 | 43 |
| 1912 | 148 |
| 1913 | 277 |
| 1914 | 407 |
| 1915 | 498 |
| 1916 | 602 |
| 1917 | 667 |
| 1918 | 714 |
| 1919 | 730 |
| 1920 | 831 |
| 1921 | 826 |
| 1922 | 856 |
| 1923 | 819 |
| 1924 | 829 |
| 1925 | 794 |
| 1926 | 781 |
| 1927 | 733 |
| 1928 | 746 |
| 1929 | 717 |
| 1930 | 759 |
| 1931 | 758 |
| 1932 | 794 |
| 1933 | 861 |
| 1934 | 865 |
| 1935 | 873 |
| 1936 | 893 |
| 1937 | 824 |
| 1938 | 813 |
| 1939 | 743 |
| 1940 | 762 |
| 1941 | 794 |
| 1942 | 702 |
| 1943 | 778 |
| 1944 | 740 |
| 1945 | 606 |
| 1946 | 800 |
| 1947 | 1,073 |
| 1948 | 1,125 |
| 1949 | 1,190 |
| 1950 | 1,378 |
| 1951 | 1,879 |
| 1952 | 1,915 |
| 1953 | 1,854 |
| 1954 | 1,678 |
| 1955 | 1,981 |
| 1956 | 1,937 |
| 1957 | 1,707 |
| 1958 | 1,643 |
| 1959 | 1,692 |
| 1960 | 1,742 |
| 1961 | 1,562 |
| 1962 | 1,497 |
| 1963 | 1,395 |
| 1964 | 1,274 |
| 1965 | 1,021 |
| 1966 | 957 |
| 1967 | 753 |
| 1968 | 664 |
| 1969 | 601 |
| 1970 | 600 |
| 1971 | 522 |
| 1972 | 444 |
| 1973 | 296 |
| 1974 | 306 |
| 1975 | 316 |
| 1976 | 329 |
| 1977 | 331 |
| 1978 | 269 |
| 1979 | 283 |
| 1980 | 319 |
| 1981 | 272 |
| 1982 | 246 |
| 1983 | 239 |
| 1984 | 198 |
| 1985 | 260 |
| 1986 | 190 |
| 1987 | 157 |
| 1988 | 246 |
| 1989 | 172 |
| 1990 | 193 |
| 1991 | 187 |
| 1992 | 194 |
| 1993 | 141 |
| 1994 | 119 |
| 1995 | 103 |
| 1996 | 82 |
| 1997 | 90 |
| 1998 | 92 |
| 1999 | 88 |
| 2000 | 36 |
| 2001 | 99 |
| 2002 | 69 |
| 2003 | 66 |
| 2004 | 115 |
| 2005 | 204 |
| 2006 | 209 |
| 2007 | 189 |
| 2008 | 222 |
| 2009 | 258 |
| 2010 | 277 |
| 2011 | 325 |
| 2012 | 402 |
| 2013 | 425 |
| 2014 | 392 |
| 2015 | 376 |
| 2016 | 471 |
| 2017 | 447 |
| 2018 | 427 |
| 2019 | 387 |
| 2020 | 343 |
| 2021 | 423 |
| 2022 | 377 |
| 2023 | 331 |
| 2024 | 288 |