Tammy is of American origin and means "twin". It is a diminutive of Tamara, which itself has multiple origins including Hebrew, Arabic, and Persian. The name gained popularity in the United States during the mid-20th century, peaking in usage in the 1960s. Tammy is often associated with the 1957 film "Tammy and the Bachelor" starring Debbie Reynolds. In popular culture, notable figures named Tammy include American actresses Tammy Blanchard and Tammy Bruce.
The name Tammy peaked in popularity during the late 1950s to early 1970s, with a significant number of births each year from 1957 to 1974, reaching its highest point in 1969 with 79 births. However, starting from the mid-1970s, the popularity of the name Tammy began to decline sharply, with fewer than 30 births per year after 1976. By the late 1980s and early 1990s, the name had become quite rare, with only single-digit numbers of births each year. Overall, there were a total of 1392 babies named Tammy from 1938 to 1999.