This name has become increasingly popular, though usually with the Addie spelling.  In fact, Addy/Addie has taken over for Maddie and Allie as one of the most frequently-heard short forms for a range of also-popular formal names, including Adeline, Adalynn, Adeliaide, and Addison. As Addy, it's the name of an American Girls doll.

Addy

Anni

The popular single-named alternative singer (born Bek) has given this cool nature-meets-surname name a new lease of life. Another notable bearer is Beck Weathers, a Texan pathologist who survived the 1996 Mount Everest disaster, which was covered in the book and film Into Thin Air.

 Outdoorsy yet refined, Beck still sits below the radar but could follow brother Beckett up the charts.

Beck

Combine the popularity of Betty White and Mad Men's glamorous Betty Draper Francis, with the residual sweetness of Ugly Betty's Betty Suarez, and the result is an impending return of the name. It's got presidential cred via Betty Ford and feminist history through Betty Friedan.
 
Betty's image is still very World War II, when Betty Grable was a hot pin-up girl and Betty was the all-American girls' name blanketing the country, second only to Mary from 1928 to 1934. 
So yes, Betty has been out for so long now that we are starting to imagine a new generation of adorable baby Bettys. We may be on the precipice of a Betty wave, thanks to Blake Lively and Ryan Reynolds, who recently chose it for their third daughter.
 
Bette Davis pronounced her name 'Betty,' while Bette Midler is 'Bet.'

Betty

Billie is a tomboy nickname name, part of the growing trend for using boyish nicknames for girls and now destined for stardom along with its most famous contemporary bearer, music sensation Billie Eilish.
 To track its path from blue to pink, Billie was 100% male in 1880, was 55% female just a decade later, in the girls' Top 100 by 1928, and is now overwhelmingly female.
 Billie is a possible retro choice for fans of jazz great Billie Holiday, born Eleanora, and a very contemporary choice for teen singer Billie Eilish -- born Billie Eilish Pirate Baird O'Connell. Other conceivable namesakes are The Wizard of Oz's Glinda--Billie Burke (born Mary William), silent screen star Billie Dove (born Bertha), actresses Billie Whitelaw and Billie Piper (born Lianne) and tennis legend Billie Jean King (born Billie). Another cultural reference is the Michael Jackson hit song 'Billie Jean.'
 Billie was picked for their daughters by Carrie Fisher, My Name is Earl actor Ethan Suplee, and Rebecca Gayheart and Eric Dane.

Billie

Brisk but rather brittle. Britt Eklund was a Bond Girl in the 1974 The Man with the Golden Gun. Britt is a contracted form of Birgit, but be aware that it does come with the strong possibility of being confused with Bret/Brett&mdash;or as a shortening of Brittany.

Britt

Cameron is still more popular as a boy's name than a girls and this simple, snappy short form works well for either sex.

Combine the charming heroine of the movie Legally Blonde with supermodel Elle Macpherson and the trend toward all names beginning with "el"—Ellie, Ella, Eleanor—and you have one hit name.
 Elle Driver is the Darryl Hannah character in Kill Bill, Elle Bishop was Kristen Bell's in Heroes, and Elle Fanning (born Mary, sister of Dakota) is a rising young actress.

Elle

Gia is a cute if slight name that calls to mind stylish sisters Mia, Lea, Pia, Tia, and Nia. One of the most familiar <a href="https://nameberry.com/baby-names/166/italian-names">Italian baby names</a> in the US, Gia is a short form of Gianna, which in turn is a diminutive of Giovanna, the feminine form of Giovanni, the Italian equivalent of John—all of them meaning "God's gracious gift."
 Gia first made a strong impression via Gia Carangi, the ill-fated supermodel whose biopic provided Angelina Jolie's breakout role in 1998. It entered the Top 1000 in 2000, and rose as high as Number 299 in 2011 before slumping down.
 Gia was chosen by Matt Damon and by Mario Lopez for their daughters and also gained recent fame as the name of the oldest daughter of Real New Jersey Housewife Teresa Giudice.

The girls have Violet and Scarlet and Ruby and Rose, but for the boys there's a much more limited palette of color names. Gray (or Grey), is one exception, which could make for a soft and evocative--if slightly somber-- choice, especially in the middle. Kaitlin Olson and Rob McElhenney recently named their son Leo Grey.
 A common surname, Gray/Grey is still an unusual first name choice--it hasn't made it into the Top 1000 in this century--while longer forms Grayson and Greyson are climbing rapidly, with Grayson at Number 97, and his twin at 200.
 The best known bearer of the name, former Governor Gray Davis of California, was born Joseph Graham Davis, Jr, and others with Gray names include Graydon Carter (born Edward Graydon), editor of "Vanity Fair," and Grayer, the child in "The Nanny Diaries."

Gray

The longer Isabella stays in the Top 10—and it's been there for more than a decade—the more we hear the nickname Izzy (especially if we watch Grey's Anatomy). it's just a matter of time before it stands on its own, as it has as a first name for the daughter of Eddie Murphy and Paige Butcher.

Izzy

Aviation enthusiast John Travolta put this fast-paced name in the lexicon when he used it for his late son, and George Lucas followed suit. 

Jett might be a word name for a kind of airplane or for the mineraloid jet, typically black and shiny, giving rise to the term "jet black".

Jett

Josie is jaunty and friendly: among the most winning of all nickname names. She's been on the <a href="https://nameberry.com/popular-names">social security list</a> since records began being kept.
 Josie and the Pussycats , revolving around an all-girl pop band, has been a pop culture phenomenon for decades, in comic books in the sixties, a Saturday morning animated cartoon series in the seventies, and as a live action movie in 2001. In a recent romcom, Drew Barrymore's character mentions that she was named after that Josie.
 While Josie is the most stylish short form for Josephine, Jo, Feeny, and even Fifi are other possibilities.

Josie

Kaye

In many minds this one belongs to Barbie, but with such positive meanings and international connections, can Ken make the transition to usability again?

Leo is a strong-yet-friendly name that was common among the Romans, used for thirteen popes, and is now at its highest point ever in the US thanks in part to Leonardo "Leo" DiCaprio.

Derived from the Latin meaning "lion", Leo is one of those names, like Luke and Finn, that many people assume must be short for something but that is authentically a complete name in its own right. That said, Leo can but short for any number of names, from Leonardo in Latinate languages to Leon and Leopold in Germanic languages. We've even heard of little girl Leonoras and Leonies called Leo: How cute is that?

Leo's simplicity makes it an international star, ranking in the Top 100 in countries as diverse as Ireland and Israel, Spain and Sweden, Austria and Australia. Leo is a truly diverse name, a perfect choice for any family crossing countries or blending cultures.
 
Leo's only real downside is its universal popularity and familiarity. If you call your child Leo, you and they will almost certainly encounter many other Leos over the years of all types and ages. Plus or minus? Or both?
 
Penelope Cruz and Javier Bardem called their son Leo, as did actress Kim Raver, NASCAR driver Jeff Gordon and Kristin Olson. 
 Famous Leos of the past include Pope Leo the Great, a number of early saints, and Leo Tolstoy, as well as Dead End Kid Gorcey, colorful baseball manager Durocher, influential gallerist Castelli and the leonine MGM icon. There have been Leos seen on everything from The West Wing to Charmed to Grey's Anatomy to Seinfeld's Uncle Leo.

Lex is still used mostly for boys, but like Alex, may cross over with the rising popularity of all long forms of the name.  Lexi is another, more feminine option.

Lula has a firecracker personality, a singing and dancing extrovert. Interesting that Lulu was a Top 100 name when the Social Security list was born in 1880, but it's been sliding ever since and has not been in the Top 1000 for decades. Modern parents in love with Lulu might well reverse that trend.
 Lulu is the now grown daughter of musicians Edie Brickell and Paul Simon. In the Swinging London sixties, Lulu was a popular single-named Scottish singer--whose birth name was Marie.

Lulu

Millie is back. It's a Top 100 name throughout much of the English-speaking world, though not yet in the US. Millicent would be an appealing long form, but many people are using Millie all by its cute self -- so many, in fact, that it returned to the Top 500 in 2015 for the first time since World War 2 and continues to climb.
Millie is a winner with parents who like their girl names offbeat, frilly, and old-fashioned. Millie is one of the coolest <a href="https://nameberry.com/search/girls-names/m">girl names starting with M</a>.
 Millie was in the Top 1000 here until 1966, peaking at Number 128 way back in 1881; it made its return appearance in 2009. The name got a lot of attention via the 1967 film Thoroughly Modern Millie, set in the 1920s, but today is more closely identified with the riveting young British actress Millie Bobby Brown who plays Eleven in the television show Stranger Things.
 Fashionable relative: Milla or Mila. Milly is also sometimes used. Tillie is another old-school nickname that, like Millie, sounds modern again.

Millie

Minnie was wildly popular at the turn of the last century — it was the fifth or sixth most popular name throughout the 1880s — but is completely obscure today. Blame Mickey's girlfriend. Regardless, it's possible that the up and coming trend toward old-fashioned nickname-names — think Maisie, Mamie, Millie — may give Minnie (all on its own, not as a short form of anything) a new moment in the sun. Minnie Driver (born Amelia) has given it some modern celeb cred. 
 There have been characters named Minnie in Dickens's Little Dorrit and Eugene O'Neill's Mourning Becomes Electra. Cab Calloway's "Minnie the Moocher" is a jazz classic.
 Minnie can really be short for just about any M name (and some non-M names as well, such as Wilhelmina), including Minerva, Mary, and Margaret.

Minnie

Posie and its near-identical twins Posy and Posey are delicate old-fashioned flower names of the type that are stylish today: Think Poppy, Marigold, Clover. 
Perhaps because it's the name of cosmetics line by Kylie Jenner, Posie is the most popular spelling of the name, followed by Posey with Posy in a distant third. and a Posie might be what you do when you take a Selfie, right?

Posie might also be a short form for butterfly name Mariposa, or even of Josephine, Sophia, or Penelope.

Posie

See the popularity graph below for the name Theo? It's been heading straight uphill since 2010, when it hopped back onto the Top 1000 after a 60+ year absence.
 
Now in the Top 100 in this form, Theo's popularity is even wider given its common use as a nickname for Theodore, which made the Top 10 for the first time in 2022. This might be the generation of Theos.
 
Theo's newfound popularity extends far beyond the US and the rest of the English-speaking world. It's currently a Top 100 name in Germany, Brazil, Scandinavia, and beyond, as well as being a popular choice for pets.
 Theo first made an impact as the name of the only son on "The Cosby Show," earlier it was associated with Vincent van Gogh's supportive brother Theo.

Theo

A straightforward, down-to-earth nickname many Walters, from Whitman to Disney, have chosen to go by. 

Walt

This pet form of such names as Winifred and Edwina and Gwendolyn has loads of vintage charm, a la Millie and Maisie, with a decidedly winning vibe. And it just got celebrity cred as the baby daughter of Jimmy Fallon.
 Winnie had been used regularly on its own in the U.S. through the early 1950's and has a number of varied namesakes. There's the Pooh, of course, and also Winnie Mandela, former wife of South African President Nelson; Winnie Cooper, the charming girlfriend of the young hero on The Wonder Years--whose given name was Gwendolyn; Winifred "Winnie" Foster, a main character in the childhood classic Tuck Everlasting; and it was also a nickname for Winston Churchill.

Winnie

daisyflowergirl's list "Short names and nicknames" of 24 great name ideas: Addy - Winnie!

Short names and nicknames

Names that are cute on their own or that work great as nicknames for longer names!