Isaac has shaved off his biblical beard and leaped into the upper echelon of popular boys' names, outrunning cousin Isaiah. A favorite of the Puritans, Isaac has never dipped below Number 400 on the US list of top boy names.

Though some might find it a bit heavy-booted, Ivan is one of the few Russian boys' names to become fully accepted into the American naming pool.

Long an extremely popular name in Spain, Iker (usually pronounced EE-kuhr in the English speaking world) is the rare Basque name that's starting to make it big in the States also, thanks to soccer player Iker Casillas. Indeed, it's been one of the fastest growing boys' names of the decade.

A name that crosses cultures, Idris was virtually unknown in the US before the emergence of the charismatic actor Idris Elba, first on The Wire and then for depicting Nelson Mandela. Since then, the name has grown with the actor and is a popular choice in the UK and Belgium, and a familiar one in The Netherlands, France, and the US.

Succinct and sharp, Ira is one of the shortest Old Testament names, belonging to one of King David's thirty 'mighty warriors.' It was widely used in the US from the 1880s to the early 1930s (it was Number 57 on the Social Security list in 1881), but fell off completely in 1993, only to return in 2016. Currently, it is in the latter half of the US Top 1000, given to around 260 boys each year.

Isidore and variants are remarkably underused and ripe for revival, a la Theodore and company.

Irvin is an Old Man name that has an uncertain future. Losing the final g in Irving makes the name slightly less dated -- but just slightly. There's something about the 'erv' sound that makes Irvin and brothers feel unappealing.

Izan, pronounced with the same vowel sounds and emphasis as Ethan, ranks among the Top 20 boys' names in Spain, where it's been popular for two decades.

Ishaan is the guardian of the Northeast in the Hindu religion.

Isabel, Theodore, and Isadora are back: could it now be time for a more widespread revival of Isidore? Yet to see any big moves up the charts, Isidore was given to more than 30 boys in a recent year: twice the number it was given to a decade ago.

Natz recommended.

An undiscovered surname possibility with upscale overtones, could be enlivened with nickname Ingo.

Another Spanish boys' name that relates to a goddess, the Egyptian Isis. San Isidro is the patron saint of Madrid.

Ishmael is most familiar through "Call me Ishmael," the opening line spoken by the youthful narrator of Moby-Dick. Few American parents have followed that advice, though the Spanish and Arabic spelling, Ismael, ranks at Number 362. With its warm and pleasant sound, though, we could see Ishmael tagging along behind Isaiah and Isaac.

Ivor, a favorite choice for upscale characters in Brit Lit novels by authors like P.G. Wodehouse and Evelyn Waugh, is an interesting and unusual name just waiting to be discovered by parents in this country.

Son of Irving.

It might be surprising to know that this name originated as a Scottish place and surname name, as in Washington Irving. It became a popular choice for first-generation Jewish-American boys, such as best-selling authors Irving Stone and Irving Wallace, whose parents looked to surnames from the British Isles to confer a measure of assimilation and class.

Itzae is an ancient Mayan name showing signs of revival in our modern world.

This name of a California desert town, used by Deborah Falconer and Robert Downey, Jr. for their son, makes a much livelier and more individual – not to mention more masculine – improvisation on the themes of India and Indiana.

Ignace is the French form of Ignatius, derived from the Latin name Ignatius, which may come from the Roman family name Egnatius of Etruscan origin. The name gained prominence through St. Ignatius of Loyola, founder of the Jesuit order. Ignace combines religious heritage with a sophisticated French flair. While never extremely common, it has maintained steady usage particularly in French-speaking regions and Catholic communities. The name carries connotations of intellectual depth, spiritual devotion, and cultural refinement. Its pronunciation (roughly ee-NYASS) adds a melodic quality that distinguishes it from the more formal Ignatius while retaining its historical significance.