The baby name Marylou appears in baby name data for the United States from 1914 to 2022. It was most popular in 1943 with 391 babies given the name.
In the later years of this period, Marylou has become less common than it once was.
| Year | Count |
|---|---|
| 1914 | 5 |
| 1915 | 18 |
| 1916 | 10 |
| 1917 | 10 |
| 1918 | 10 |
| 1919 | 28 |
| 1920 | 13 |
| 1921 | 20 |
| 1922 | 12 |
| 1923 | 74 |
| 1924 | 83 |
| 1925 | 48 |
| 1926 | 124 |
| 1927 | 353 |
| 1928 | 211 |
| 1929 | 224 |
| 1930 | 191 |
| 1931 | 198 |
| 1932 | 179 |
| 1933 | 222 |
| 1934 | 267 |
| 1935 | 304 |
| 1936 | 258 |
| 1937 | 321 |
| 1938 | 277 |
| 1939 | 292 |
| 1940 | 285 |
| 1941 | 291 |
| 1942 | 346 |
| 1943 | 391 |
| 1944 | 283 |
| 1945 | 228 |
| 1946 | 286 |
| 1947 | 248 |
| 1948 | 313 |
| 1949 | 260 |
| 1950 | 269 |
| 1951 | 264 |
| 1952 | 192 |
| 1953 | 181 |
| 1954 | 165 |
| 1955 | 150 |
| 1956 | 157 |
| 1957 | 245 |
| 1958 | 226 |
| 1959 | 213 |
| 1960 | 218 |
| 1961 | 329 |
| 1962 | 100 |
| 1963 | 145 |
| 1964 | 102 |
| 1965 | 71 |
| 1966 | 46 |
| 1967 | 46 |
| 1968 | 35 |
| 1969 | 22 |
| 1970 | 60 |
| 1971 | 41 |
| 1972 | 20 |
| 1973 | 17 |
| 1974 | 5 |
| 1975 | 15 |
| 1976 | 9 |
| 1977 | 10 |
| 1978 | 30 |
| 1979 | 5 |
| 1980 | 5 |
| 1981 | 10 |
| 1982 | 14 |
| 1983 | 10 |
| 1984 | 15 |
| 1985 | 33 |
| 1986 | 20 |
| 1987 | 23 |
| 1988 | 15 |
| 1995 | 6 |
| 1996 | 10 |
| 1999 | 10 |
| 2007 | 8 |
| 2010 | 5 |
| 2014 | 6 |
| 2022 | 10 |