The baby name Masao appears in baby name data for the United States from 1912 to 1935. It was most popular in 1918 with 85 babies given the name.
In the later years of this period, Masao has become less common than it once was.
| Year | Count |
|---|---|
| 1912 | 24 |
| 1913 | 30 |
| 1914 | 38 |
| 1915 | 40 |
| 1916 | 66 |
| 1917 | 65 |
| 1918 | 85 |
| 1919 | 78 |
| 1920 | 46 |
| 1921 | 61 |
| 1922 | 81 |
| 1923 | 66 |
| 1924 | 72 |
| 1925 | 46 |
| 1926 | 48 |
| 1927 | 48 |
| 1928 | 40 |
| 1929 | 34 |
| 1930 | 32 |
| 1931 | 10 |
| 1932 | 16 |
| 1933 | 20 |
| 1934 | 14 |
| 1935 | 12 |