Jack may have fallen from its Number 1 place in England, but in the US it's as popular as it was at its height in the 1920s and 1930s. A durable, cheery, everyman form of John, Jack ranks as one of the most popular boy names starting with J.

Josie is jaunty and friendly: among the most winning of all nickname names. She's been on the Social Security list since records began being kept.

Jordan became one of the top unisex baby names in the heyday of basketball's Michael Jordan, and is still among the most popular unisex names starting with J. The name was originally given to those baptized in holy water brought back by Crusaders from the River Jordan, the only river in Palestine, and the one in which Christ was baptized by John the Baptist.

King David's father turned 1980s cowboy, Jesse is now down in popularity but still a Biblical classic, ranking in the US Top 1000 for its entire history. The name is associated with a wide variety of bearers, from outlaw Jesse James to Olympic athlete Jesse Owens to activist Jesse Jackson to current actors Jesse Tyler Ferguson and Jesse Eisenberg. The spelling Jesse is more usual as a boys' name while Jessie is more traditional for girls.

The cool form of James in the 1970s and '80s for both sexes. Still a more stylish short form than Jimmy, though many parents will want to call James by his entire, not-very-long name.

Reminiscent of 70’s favorite Jason, and sharing sounds with the perpetually popular James, Jayden is one of the more enduring members of the -ayden trend.

Using the 'ie' ending makes Johnny slightly more feminine, which must have been what Melissa Etheridge was thinking when she named one of her twins Johnnie Rose.

Jacky is a masculine name commonly used as a diminutive of Jack or Jacob, though it sometimes stands as an independent given name. Jack derives from John, meaning 'God is gracious,' while Jacob means 'supplanter' in Hebrew. With its friendly 'y' ending, Jacky has an approachable, boyish charm that can transition from childhood to adulthood. The name was particularly popular in the mid-20th century but has become less common as a formal name in recent decades. Jacky has cross-cultural appeal, recognized in various English-speaking countries. It's worth noting that the spelling 'Jackie' is often associated with the feminine version, though both spellings have been used for boys. The name carries a casual, unpretentious quality with a touch of nostalgic appeal.

Unplain (if dated) Jane.

The number one surname in Denmark could make a sophisticated and stylish girl's name. Jensen Huang is the (male) cofounder of AI giant Nvidia.