The baby name Marilou appears in baby name data for the United States from 1923 to 1996. It was most popular in 1927 with 102 babies given the name.
In the later years of this period, Marilou has become less common than it once was.
| Year | Count |
|---|---|
| 1923 | 12 |
| 1924 | 12 |
| 1926 | 31 |
| 1927 | 102 |
| 1928 | 66 |
| 1929 | 64 |
| 1930 | 89 |
| 1931 | 43 |
| 1932 | 62 |
| 1933 | 40 |
| 1934 | 78 |
| 1935 | 36 |
| 1936 | 26 |
| 1937 | 32 |
| 1938 | 40 |
| 1939 | 17 |
| 1940 | 33 |
| 1941 | 18 |
| 1942 | 39 |
| 1943 | 32 |
| 1944 | 26 |
| 1945 | 63 |
| 1946 | 22 |
| 1947 | 56 |
| 1948 | 57 |
| 1949 | 34 |
| 1950 | 57 |
| 1951 | 77 |
| 1952 | 67 |
| 1953 | 65 |
| 1954 | 53 |
| 1955 | 33 |
| 1956 | 25 |
| 1957 | 46 |
| 1958 | 12 |
| 1959 | 6 |
| 1960 | 34 |
| 1961 | 22 |
| 1962 | 5 |
| 1963 | 6 |
| 1964 | 11 |
| 1979 | 6 |
| 1996 | 7 |