The name Johnny is a diminutive form of the masculine given name John, which has origins tracing back to the ancient Hebrew name Yohanan. This name is derived from the roots yo, meaning "Yahweh," and hanan, meaning "he was gracious." The name John gained popularity during the Christian era due to its association with John the Baptist and John the Apostle, both prominent figures in the New Testament.

The earliest recorded use of the name Johnny dates back to the late 16th century in England. It was a common nickname for John, particularly among the working class and rural communities. The diminutive form "Johnny" was used as a term of endearment or familiarity, often referring to young boys or men of lower social standing.

One of the earliest and most famous references to the name Johnny can be found in the traditional English nursery rhyme "Johnny Johnny Yes Papa," which dates back to the early 18th century. This rhyme became a popular children's song and helped to further popularize the name.

Throughout history, there have been several notable individuals named Johnny. One of the most famous was Johnny Appleseed, born John Chapman (1774-1845), an American pioneer nurseryman who introduced apple trees to large parts of Pennsylvania, Ontario, Ohio, Indiana, and Illinois. Another well-known Johnny was Johnny Weissmuller (1904-1984), an Austrian-American swimmer and actor best known for portraying Tarzan in several films during the 1930s and 1940s.

In the world of music, Johnny Cash (1932-2003) was an iconic American singer-songwriter who became known as the "Man in Black" and is widely regarded as one of the most influential musicians of the 20th century. Johnny Ramone (1948-2004), born John William Cummings, was the guitarist and co-founder of the influential punk rock band The Ramones.

In the realm of sports, Johnny Unitas (1933-2002) was a legendary American football quarterback who played for the Baltimore Colts and is considered one of the greatest players in the history of the National Football League (NFL).

While the name Johnny has its roots in ancient Hebrew, it has become a beloved and familiar nickname in various cultures around the world, particularly in English-speaking countries. Its enduring popularity can be attributed to its association with famous figures, cultural references, and its ability to convey a sense of familiarity and warmth.