Catherine is one of the oldest and most consistently well-used girls’ names, with endless variations and nicknames. The Catherine form feels more gently old-fashioned and feminine than the more popular K versions. Most stylish nickname for Catherine right now: Kate...or Cate, a la Blanchett.

Katherine is one of the oldest, most diverse, and all-around best names: it's powerful, feminine, royal, saintly, classic, popular, and adaptable. Long one of the top girls' names starting with K, Katherine has now been unseated on the popularity list by upstarts Kennedy and Kinsley, but a dip in popularity only adds to its charm.

Kate, in the headlines via Catherine Middleton aka the Princess of Wales, has been as pervasive as Kathy was in the 1950s and 1960s, both as a nickname for Katherine and Kaitlyn and as a strong, classic stand-alone name.

Karen, a once sweet Danish import, was so popular during the baby boom (Karen was Number 3 in 1960) that it's become a mem in recent years, representing a hostile white woman—one who usually wants to speak with the manager.

Friendly mega-popular short form of Katherine that has definitively replaced Kathy, Katie is often given on its own. Going forward, though, Katie is more stylishly clipped itself to the grownup Kate.

This endearing nickname name is one Katherine pet form that predates all the Kathys and Katies, having been fairly common in the eighteenth century. With the current mini-craze for animal-related names, Kitty is sounding cute and cuddly again—she's already jumped back onto the U.K. list, at number 199.

Kathleen is the early Irish import version that came between Katherine and Kaitlin, and which hasn't been used in so long it's almost beginning to sound fresh again. It was a surprise pick by one of the hip Dixie Chicks, Martie Maguire. Kathleen was a Top 10 name from 1948 to 1951, and it is the subject of several old sentimental songs, such as "I'll Take You Home Again, Kathleen."

Carina is a pretty delicately feminine name whose fall from popularity is not helped by its similarity to hurricane name Katrina or slang victim Karen.

Although the Kathryn spelling feels like a modern streamlining of this ancient royal and saints' name, it is in fact found back through history. At least one of Henry the Eighth's unfortunately wives sometimes spelled her name as Kathryn.

A widely used name, Kaylee pulls together something from Kayla and something from Hailey, yet somehow loses something in the process. It has surpassed cousin Kayla on the charts and is one of three girls' names starting with Kthat ranks in the US Top 100.

This sweet and loving name, favored in recent years by a mix of Hispanic-American parents and Bob Dylan fans, was chosen for her daughter by TV actress Melina Kanakaredes.

This name of a touristed island in sight of Los Angeles makes an attractive and newly stylish variation on the classic Catherine or overused Caitlin.

Katerina and its near-identical twin Katarina have a pleasingly lilting European sound, though for some Americans they may be uncomfortably close to Katrina, which will be linked for a long time to the hurricane that devastated New Orleans.

An Irish and Welsh form of Catherine, Caitlin was a boom name of the eighties, rocketing from obscurity (Americans first heard it via the wife of doomed poet Dylan Thomas) to the height of popularity in the space of a decade. The original name was gradually eclipsed by its myriad spelling variations -- Katelyn and Kaitlyn both soon topping it on the popularity lists.

One of those short, punchy names with its roots in a variety of different cultures and languages, Rina is sister to names like Mina, Mira, Lina, and Nina. Retro in feel, but never overused in the US, it peaked in 1980 when it was given to 90 girls.

One of the most popular of the trendy Caitlin variations, Katelyn points directly to components Kate and Lyn --making it a bit more traditionally feminine.

The hurricane blew this one out of the realm of possibility.

A huge name in the late 90's and most of the 00's, Kaitlyn's been on a downward trend in recent years. Kaitlyn and its soundalikes have been so well used in the US that they can no longer be seen as fresh, but it's still relatively popular in Canada.

We're hearing Kat more and more being used by Katherines who are tired of Kathy, Kate and Katie. Katti or Kattie is another possibility.

One of the warm and earthy Russian nickname names now coming into style. Denzel Washington gave his daughter the Katia spelling.