Lennis is a rare name used for both girls and boys that was most common in the 1940s and has all but disappeared.
Lennis is predominantly a boy name. It last appears in U.S. records in 2013. Lennis first appears in 1898 and peaked in 1948 (33 births).
| Year | U.S. births | U.S. + territories | ♀ Rank | ♂ Rank |
|---|---|---|---|---|
| 2013 | 5 | 5 | — | #13,277 |
| 2012 | 5 | 5 | — | #13,425 |
| 2001 | 13 | 13 | #16,831 | #8,016 |
| 1997 | 5 | — | — | #10,185 |
| 1991 | 5 | — | — | #9,050 |
| 1989 | 6 | — | — | #7,526 |
| 1988 | 5 | — | — | #8,022 |
| 1986 | 6 | — | — | #6,392 |
| 1985 | 9 | — | — | #4,544 |
| 1984 | 7 | — | — | #5,321 |
| 1983 | 9 | — | — | #4,351 |
| 1981 | 10 | — | — | #4,024 |
| 1980 | 6 | — | — | #5,953 |
| 1978 | 5 | — | — | #6,378 |
| 1977 | 19 | — | #10,511 | #2,991 |
| 1976 | 8 | — | — | #4,245 |
| 1975 | 10 | — | — | #3,571 |
| 1974 | 7 | — | — | #4,433 |
| 1973 | 5 | — | — | #5,557 |
| 1971 | 12 | — | — | #2,913 |
| 1970 | 12 | — | — | #2,814 |
| 1969 | 15 | — | — | #2,268 |
| 1968 | 17 | — | — | #2,001 |
| 1967 | 14 | — | — | #2,214 |
| 1966 | 12 | — | — | #2,403 |
| 1965 | 17 | — | — | #1,965 |
| 1964 | 13 | — | — | #2,368 |
| 1963 | 16 | — | — | #2,084 |
| 1962 | 25 | — | #5,112 | #2,005 |
| 1961 | 18 | — | — | #1,978 |
| 1960 | 31 | — | #6,066 | #1,647 |
| 1959 | 22 | — | #5,322 | #2,163 |
| 1958 | 29 | — | #4,724 | #1,753 |
| 1957 | 29 | — | #5,772 | #1,700 |
| 1956 | 30 | — | #5,082 | #1,668 |
| 1955 | 33 | — | #5,543 | #1,498 |
| 1954 | 41 | — | #4,140 | #1,352 |
| 1953 | 40 | — | #3,849 | #1,394 |
| 1952 | 40 | — | #3,123 | #1,480 |
| 1951 | 38 | — | #3,398 | #1,441 |
| 1950 | 30 | — | #4,158 | #1,595 |
| 1949 | 35 | — | #3,091 | #1,567 |
| 1948 | 45 | — | #3,065 | #1,270 |
| 1947 | 51 | — | #2,318 | #1,313 |
| 1946 | 37 | — | #2,195 | #1,726 |
| 1945 | 25 | — | #3,856 | #1,609 |
| 1944 | 29 | — | #2,858 | #1,660 |
| 1943 | 34 | — | #2,502 | #1,614 |
| 1942 | 26 | — | #5,021 | #1,565 |
| 1941 | 34 | — | #3,143 | #1,357 |
| 1940 | 28 | — | #4,727 | #1,420 |
| 1939 | 36 | — | #2,678 | #1,346 |
| 1938 | 27 | — | #3,066 | #1,655 |
| 1937 | 25 | — | #3,310 | #1,722 |
| 1936 | 29 | — | #2,611 | #1,618 |
| 1935 | 22 | — | #3,320 | #1,994 |
| 1934 | 30 | — | #2,240 | #1,820 |
| 1933 | 27 | — | #2,787 | #1,744 |
| 1932 | 26 | — | #2,432 | #2,155 |
| 1931 | 27 | — | #3,367 | #1,671 |
| 1930 | 27 | — | #3,875 | #1,676 |
| 1929 | 34 | — | #2,057 | #1,898 |
| 1928 | 26 | — | #2,883 | #2,112 |
| 1927 | 21 | — | #5,243 | #2,090 |
| 1926 | 41 | — | #2,306 | #1,498 |
| 1925 | 21 | — | #3,529 | #2,525 |
| 1924 | 21 | — | #2,893 | #3,148 |
| 1923 | 31 | — | #2,538 | #1,988 |
| 1922 | 24 | — | #3,855 | #2,107 |
| 1921 | 27 | — | #3,557 | #1,951 |
| 1920 | 21 | — | #4,208 | #2,291 |
| 1919 | 16 | — | #4,062 | #3,018 |
| 1918 | 22 | — | #2,332 | #3,557 |
| 1917 | 40 | — | #2,263 | #1,418 |
| 1916 | 24 | — | #2,580 | #2,337 |
| 1915 | 21 | — | #2,809 | #2,382 |
| 1914 | 15 | — | #3,417 | #2,373 |
| 1912 | 16 | — | #2,060 | #2,155 |
| 1911 | 6 | — | #2,341 | — |
| 1906 | 5 | — | #2,093 | — |
| 1903 | 6 | — | #1,700 | — |
| 1899 | 8 | — | #1,240 | — |
| 1898 | 9 | — | #1,219 | — |