Thelbert is a rare boys' name that was most common in the 1920s and has all but disappeared.
Thelbert is a boy name. It last appears in U.S. records in 1985. Thelbert first appears in 1908 and peaked in 1921 (32 births).
| Year | U.S. births | U.S. + territories | Rank |
|---|---|---|---|
| 1985 | 5 | — | #7,489 |
| 1983 | 5 | — | #7,234 |
| 1980 | 7 | — | #5,470 |
| 1974 | 5 | — | #5,931 |
| 1972 | 6 | — | #4,944 |
| 1971 | 8 | — | #3,935 |
| 1968 | 7 | — | #3,642 |
| 1964 | 8 | — | #3,262 |
| 1963 | 7 | — | #3,620 |
| 1961 | 7 | — | #3,629 |
| 1960 | 9 | — | #3,051 |
| 1959 | 8 | — | #3,258 |
| 1958 | 11 | — | #2,631 |
| 1957 | 8 | — | #3,230 |
| 1955 | 11 | — | #2,539 |
| 1954 | 11 | — | #2,581 |
| 1953 | 12 | — | #2,381 |
| 1952 | 12 | — | #2,366 |
| 1951 | 8 | — | #3,043 |
| 1950 | 10 | — | #2,566 |
| 1949 | 21 | — | #1,665 |
| 1948 | 22 | — | #1,604 |
| 1947 | 16 | — | #1,983 |
| 1946 | 11 | — | #2,389 |
| 1945 | 12 | — | #2,120 |
| 1944 | 10 | — | #2,457 |
| 1943 | 20 | — | #1,629 |
| 1942 | 16 | — | #1,859 |
| 1941 | 17 | — | #1,752 |
| 1940 | 12 | — | #2,171 |
| 1939 | 19 | — | #1,573 |
| 1938 | 24 | — | #1,395 |
| 1937 | 22 | — | #1,480 |
| 1936 | 26 | — | #1,321 |
| 1935 | 18 | — | #1,704 |
| 1934 | 20 | — | #1,604 |
| 1933 | 19 | — | #1,638 |
| 1932 | 18 | — | #1,774 |
| 1931 | 25 | — | #1,424 |
| 1930 | 25 | — | #1,492 |
| 1929 | 17 | — | #1,920 |
| 1928 | 24 | — | #1,564 |
| 1927 | 20 | — | #1,790 |
| 1926 | 21 | — | #1,710 |
| 1925 | 20 | — | #1,793 |
| 1924 | 29 | — | #1,411 |
| 1923 | 20 | — | #1,804 |
| 1922 | 25 | — | #1,543 |
| 1921 | 32 | — | #1,324 |
| 1920 | 22 | — | #1,688 |
| 1919 | 21 | — | #1,686 |
| 1918 | 20 | — | #1,763 |
| 1917 | 20 | — | #1,687 |
| 1916 | 16 | — | #1,937 |
| 1915 | 26 | — | #1,338 |
| 1914 | 10 | — | #2,252 |
| 1913 | 21 | — | #1,144 |
| 1912 | 10 | — | #1,730 |
| 1911 | 9 | — | #1,284 |
| 1909 | 5 | — | #1,659 |
| 1908 | 5 | — | #1,571 |