A popular name in Denmark, in this country Bo has some cowboy swagger and a lot of substance in its minimal two letters.
In Mandarin Chinese, Bo means "wave".

Braydn, an imaginative spelling of Braden and cousin of all the other aden-ending boys' names, has been on the popularity lists since 2002, though its star is fading.

Bradyn

Brantley is one of several English surnames that was new to the tops in 2009. A possible-probable inspiration is the country rock singer Brantley Gilbert.

Brantley

Brayden is the top spelling of one of the epidemically popular rhyming cousins of Aiden, hitting the Top 100 in 2005.. It has dipped a bit recently, but is still widely used. Other popular spellings include Braden, Braeden, Braydon, Braiden, Braedon and Bradyn. Take your pick.
 Actress Melissa Joan Hart named her son Braydon.

Brayden

Casey is a name with a big wide grin, Irish, friendly, and open, and associated with several American folk heroes--Casey Jones, the engine driver of the Cannonball Express who gave his life to save his passengers, and the legendary Casey at the Bat.
 Casey was at its height of popularity in the 1980s bur recently has started climbing the charts again in the US, maybe because some of the Caseys born in the 1980s have become famous in the 2020s.

Casey

With the popular 'ash' sound and a contemporary feel, Cash is a widely used name in the US. Used occasionally before the 2000s, Cash really took off in 2003, following the death of American musical legend, Johnny Cash. 
 
Cash could be considered an old occupational name, derived from the Latin capsa, meaning someone who makes boxes. It also, and perhaps more obviously, is an English word for money, giving it a slightly celebrity-name vibe, along the lines of Saint, Sir, and Legendary. 
 An alternative origin for the name could be as a derivative of the Roman names, Cassius and Cassian, which are sometimes pronounced as "cash-us" or "cash-un". This could lend the name some additional history, along with the meaning "empty" "hollow" or "vain" (and therefore, maybe just a touch of irony).
 Celebrities including Annabeth Gish, Joshua Morrow, John Rich, Finola Hughes and Russell Young, have used Cash for their sons, and as of 2023, it is a Top 200 choice in the US.
 Until 2021, Cash was always the preferred spelling, however in more recent years, the variation Kash has ranked slightly higher. Given to over 1100 babies each year, Cash has seen a slightly decline, but nevertheless, remains in style.

Cash

Chase, with its sleek and ultraprosperous aura, is redolent of the worlds of high finance and international banking. Chase has been well used during the last few decades, seen as a character on 24 and on several young-audience shows. 
 There are a disproportionate number of football stars name Chase.

Chase

In the early 1990s, Cody was in the Top 25 most popular <a href="https://nameberry.com/boys-names">boys' names</a> in the USA; but it has been in decline since then. It retains a greater degree of popularity in the UK, however. Cody might be short for Dakota but despite its nickname feeling, it's a name of its own.

Cody

Former teen idol name, now middle-aged. This name has been on a steady decline since the early-1990s.

Corey

Emery is one of the newly popular Em- names that has great potential, though right now for girls more than boys: it received a boost in 2009, a year after Angie Harmon and Jason Sehorn used it for one of their daughters. 

Emery ranks on the Top 1000 for both boys and girls, but all the way up in the Top 100 for girls and down in the 700s for boys. Many <a href="https://nameberry.com/blog/baby-name-trends-em-names-beyond-emily-and-emma">related names</a> are also trending for baby boys, from Emerson to Emrys to Amory to Emmett.

Emery

Biblical Jacob ceded his Number 1 spot to biblical Noah, in 2013, after holding first place on the list of <a href="https://nameberry.com/boys-names">baby boy names</a> from 1999 to 2012, given a huge boost by the Twilight phenomenon.
 
Jacob has widespread appeal to a range of parents, with an image of honesty and warmth. Another plus is the friendly nickname Jake — also given on its own to thousands of boys every year — which shares the cool-yet-earthy appeal of equally stylish cousins Max and Sam. 
 Jacob comes from the Latin name Iacobus, which was ultimately derived from the Hebrew name Ya’aqov. In the Old Testament, Jacob was one of the most important patriarchs of the tribes of Israel. He was the youngest son of Isaac and Rebecca and the twin brother of Esau, as well as the husband of both Leah and Rachel. The 12 tribes of Israel evolved from his 12 sons.
 Jacob is still among the most popular <a href="https://nameberry.com/search/boys-names/j">boy names starting with J</a>, along with James, Jack, and Jackson, and is Number 1 for boys among <a href="https://nameberry.com/blog/gen-z-names">Gen Z names</a>.
 
The downside is that Jacob is at this point way overused. Jacoby is one trendy variation. Jakob, meanwhile, is an alternate spelling used by the Dutch, Scandinavians and Germans. Some interesting international versions include the Scottish Hamish, the Cornish Jago, and the Dutch Jaap.

Jacob

A popular member of the -ayden family, Kaden ranks alongside Kaiden, Kayden, Kasen, Kade, Caiden, Cade, and Caden in the US Top 1000. A 90s invention that took off in the 2000s, Kaden is concise and modern, with its popular K initial. 

The name is possibly derived from the Celtic and Irish given name Cadan, meaning "battle", however, it is equally likely to have been inspired by the Old English surname Cade, meaning "round" or "gentle", which rose to popularity just a few years before the Kaden family.
 
Recent namesakes include English footballer Kaden Rodney, Australian cyclist Kaden Groves, influencer Kaden Hammond, and American footballers Kaden Smith and Kaden Elliss. 
 
Kaden ranks at the latter end of the US Top 300, and is given to over 1100 babies every year. However, because of the number of different spelling variants,<a href="https://nameberry.com/blog/2023-playground-analysis">playground analysis</a> suggests that sound-wise at least, it might feel more like a Top 20 name.

Kaden

Kaleb is one of several <a href="https://nameberry.com/search/boys-names/k">boys' names starting with k</a> that started life as a classic C name, Caleb. Kevin Federline named his boy Kaleb Michael Jackson.

Kaleb

Maddox, a previously obscure Welsh family name with a powerfully masculine image, suddenly came into the spotlight when Angelina Jolie chose it for her son in 2003. By the following year it was in the middle of the Top 1000, and it has risen since.
 It was Maddox who set the precedent for all the boys in the Jolie-Pitt clan to have names ending in 'x'-and helped fuel the spark for all names X. 
 Maddox is related to the traditional Welsh Madoc (pronounced MAH-dog), meaning 'fortunate'; it belonged to a bearer who, according to legend, colonized North America in the twelfth century.
 Maddox is a character in The Vampire Diaries; spelled Madox, it appeared in Michael Ondaatje's The English Patient.

Maddox

Though ancient, Marcus now sounds more current than Mark, in tune with today's trend towards us-ending Latinate names.
 Marcus, which is thought to be related to Mars, the god of war, was commonplace in classical Rome--not surprising as it was one of only about a dozen given names in use then. Among the most prominent were the emperor and stoic philosopher Marcus Aurelius, the Marcus known to us as Mark Antony, and the politician, philosopher and orator Cicero.
 Dr Marcus Welby was a staple on vintage TV, and since then we have seen the name in both the Harry Potter and Twilight franchises, as the protagonist of Nick Hornby's About a Boy, on Sons of Anarchy and Men of a Certain Age, and in Indiana Jones, The Blind Side, and Bad Santa.
 Marcus Loew was the movie magnate behind MGM and Loew's theatres, and Marcus Allen was an Oakland Raiders superstar.
 Marius is a related possibility.

Marcus

Marshall is an occupational surname, not having to do with anything military or martial, but stemming from the Norman French for someone caring for horses. It's been used as a first name since the nineteenth century and has been on the Social Security list since it started to publish its data in 1880.
 Marshall is the real name of rapper Eminem, and it got some attention during the heyday of communications maven Marshall McLuhan. Peyton Manning named his son Marshall, and Jason Segel played the character of Marshall Eriksen on How I Met Your Mother.

Marshall

Radley

A slim, elegant, silvery surname, Reed could be a banker or a sculptor, and therein lies the appeal of this simple yet distinctive name. The versatile Reed can be seen as a grass-like nature name and a musical name.
 There have been Reeds on Grey's Anatomy and Party of Five, as well as on the big screen in Boogie Nights. Reed Richards was the human name of the scientific genius who became Mr. Fantastic of the Fantastic Four.
 The many notables who wore Reed as a surname include army surgeon Walter, basketball coach Willis, Brady Bunch dad Robert, critic Rex, director Sir Carol, actors Donna and Oliver, and singer-songwriter Lou.
The name can also be spelled Reid.

Reed

An Anglicized spelling of the Welsh Rhys, this traditional boys' name got a big boost for girls in the early 2000s, thanks to the high-profile Ms. Witherspoon (who was actually born Laura Jeanne Reese, her second middle being her mother's maiden name). This spelling has been on the decline for boys since 2003, possibly for the same reason, but remains a strong, simple choice which might pose fewer spelling and pronunciation issues outside of the UK than the Welsh original.

Reese

This more elaborate but not unfamiliar spelling of Riley feels oddly more feminine.  Designer and Beatle daughter Stella McCartney has a daughter named Reilley.  Still, Reilly or more common Riley is one name that's remained popular for both boys and girls.

Reilly

Parents seeking alternatives to the overexposed Ryan have flocked to this soundalike name, which peaked at #146 in 2011. 

Rylan

The -ee suffix is decisively feminine, so it's no surprise that male usage of this name lags behind female usage.

Rylee

Has a laid-back rural feel some would associate with country singer Travis Tritt; Kyra Sedgwick and Kevin Bacon chose it for their son. Travis Scott, born Jacques Webster Jr., a popular rap artist, is another famous Travis.

Travis

jjn1jkj's list "Boy Names Jen likes" of 23 great name ideas: Bo - Travis!