The baby name Dorthea appears in baby name data for the United States from 1913 to 1970. It was most popular in 1921 with 39 babies given the name.
In the later years of this period, Dorthea has become less common than it once was.
| Year | Count |
|---|---|
| 1913 | 6 |
| 1914 | 6 |
| 1915 | 13 |
| 1916 | 12 |
| 1917 | 11 |
| 1918 | 5 |
| 1919 | 5 |
| 1920 | 10 |
| 1921 | 39 |
| 1922 | 20 |
| 1923 | 6 |
| 1924 | 34 |
| 1925 | 14 |
| 1926 | 17 |
| 1927 | 7 |
| 1930 | 6 |
| 1934 | 7 |
| 1935 | 6 |
| 1950 | 10 |
| 1952 | 5 |
| 1954 | 15 |
| 1955 | 12 |
| 1958 | 10 |
| 1959 | 10 |
| 1962 | 5 |
| 1964 | 5 |
| 1965 | 10 |
| 1966 | 5 |
| 1970 | 7 |