Merwyn is a rare boys' name that was most common in the 1930s and has all but disappeared.
Merwyn is predominantly a boy name. It last appears in U.S. records in 1971. Merwyn was first reported in SSA data in 1912 and peaked in 1937 (38 births).
| Year | U.S. births | U.S. + territories | ♀ Rank | ♂ Rank |
|---|---|---|---|---|
| 1971 | 6 | — | — | #4,740 |
| 1969 | 6 | — | — | #4,250 |
| 1968 | 5 | — | — | #4,535 |
| 1962 | 7 | — | — | #3,528 |
| 1958 | 6 | — | — | #3,797 |
| 1957 | 9 | — | — | #2,956 |
| 1956 | 7 | — | — | #3,425 |
| 1955 | 8 | — | — | #3,126 |
| 1953 | 6 | — | — | #3,665 |
| 1952 | 5 | — | — | #4,098 |
| 1951 | 5 | — | — | #4,073 |
| 1950 | 8 | — | — | #2,946 |
| 1949 | 8 | — | — | #2,937 |
| 1948 | 7 | — | — | #3,211 |
| 1947 | 14 | — | — | #2,139 |
| 1946 | 14 | — | — | #2,003 |
| 1945 | 5 | — | — | #3,624 |
| 1944 | 13 | — | — | #2,051 |
| 1943 | 17 | — | — | #1,806 |
| 1942 | 14 | — | — | #2,020 |
| 1941 | 22 | — | — | #1,475 |
| 1940 | 30 | — | — | #1,241 |
| 1939 | 24 | — | — | #1,382 |
| 1938 | 36 | — | — | #1,086 |
| 1937 | 38 | — | — | #1,050 |
| 1936 | 31 | — | — | #1,199 |
| 1935 | 28 | — | — | #1,288 |
| 1934 | 34 | — | — | #1,144 |
| 1933 | 28 | — | — | #1,271 |
| 1932 | 19 | — | — | #1,694 |
| 1931 | 22 | — | — | #1,521 |
| 1930 | 28 | — | — | #1,386 |
| 1929 | 21 | — | — | #1,652 |
| 1928 | 12 | — | — | #2,484 |
| 1927 | 24 | — | — | #1,586 |
| 1926 | 23 | — | — | #1,598 |
| 1925 | 24 | — | #5,529 | #1,848 |
| 1924 | 18 | — | — | #1,944 |
| 1923 | 18 | — | — | #1,921 |
| 1922 | 17 | — | — | #2,007 |
| 1921 | 13 | — | — | #2,462 |
| 1920 | 18 | — | — | #1,936 |
| 1919 | 11 | — | — | #2,613 |
| 1918 | 16 | — | — | #2,044 |
| 1917 | 14 | — | #5,066 | #2,879 |
| 1916 | 19 | — | — | #1,678 |
| 1915 | 5 | — | — | #4,195 |
| 1914 | 11 | — | — | #2,060 |
| 1913 | 14 | — | — | #1,482 |
| 1912 | 8 | — | — | #1,995 |