Standard practice in Japan, combined with Honorifics. First name + honorific is more intimate, and yobisute (null honorific) even more so.
Standard practice in all armed forces around the world.
Not at all uncommon in many British schools (especially in all-male situations such as PE), and not just the posh public schools that the stereotype tends to suggest, either.
A vast majority of political figures are referred mainly by their last name, unless they get some kind of nickname (JFK).
The main exceptions to this being some female politicians and political legacies whose last names aren't distinctive enough (Hillary Clinton, almost universally referred to as "Hillary", is an example of both). Saddam Hussein was almost always referred to as "Saddam," presumably because "Hussein" is an all-too-common name in the Arab world.
Saddam is just as common a first name as Hussein is as a surname. "Saddam Hussein" in the Arab world is about as distinctive as John Smith. Why the world came to refer to Saddam on a first name basis isn't clear, but it may have been propagated by Saddam himself as part of his cult of personality.
Before the first Gulf War, King Hussein of Jordan was also frequently in the news. There was confusion until the media settled on "Saddam".
One extreme example was Abraham Lincoln. He didn't like the name Abe or Abraham and even his family and friends addressed him as Lincoln.
This is ironic, since he's an example of an American President who's commonly called by his first name (and often the diminutive form).
This is more often than not the case in the United States military. It can lead to confusion with common last names, however, so the form of address may be modified to "Rank Last Name" in units were there is more than one soldier with the same last name, or an appropriate informal title such as Top, Gunny or Chief may be substituted.
This is probably so in EVERY military in the world, where you are only "allowed" to refer to others by first name within your own or a lower rank group. Also, last names are usually visible on the uniform, so you hear the last names of your comrades frequently and place them to faces more easily.
Not the case in the IDF. Israelis are generally very, very informal, speaking to complete strangers their age with the language they’d use for a close friend. This is a bit toned down in the army, but even then soldiers sometimes refer to their direct commanders by their first name.
In the Army, the Last Name rule is less common among the commissioned officer ranks, where a superior officer often calls peers and subordinates by their first name. Enlisted soldiers are told to stick with last names, as an unofficial rule. Note that the rule never applies when speaking to a superior: use their title only.
In most of the US military, it is always more polite to address a superior officer as "sir" or "ma'am" than by any specific title, with the exception of generals, who should be addressed as "general".
Part of this stems from the ideal of professionalism; part of it is because during basic training, nobody in charge really cares about your first name.
In cultures where First Name Basis is normal, a person with a common first name but an uncommon last name might be addressed on Last Name Basis by their friends and peers, just because it's a more distinctive name.
The Norwegian explorer Nansen famously suggested to his companion Johansen, after weeks of sharing a sleeping bag to survive an arctic winter, that they should start using each other's first names.
Almost universal in sports, where announcers and coaches will refer to the players almost exclusively using their last names. Even some teammates will refer to one another in a Last Name Basis. Relatedly, it's typically only the last name that appears on the player's uniform.
Fans also typically refer to sports figures only by their last name, with only a few exceptions (Kobe Bryant is "Kobe," Shaquile O'Neal is "Shaq," etc.).
The most famous exception is that Brazilian soccer players usually have their nicknames on their uniforms. Only Known by Their Nickname is the usual norm.
The same is true in capoeira, a Brazilian martial art, as well; one can know someone for years by their capoeira name—e.g., Mestre Bimba—before finding out their real name (Manoel dos Reis Machado). Even historians of capoeira might not recognize the name Machado if they heard it.
AP Style for news writing dictates that, after the first mention of someone in an article, all other references use only their last name. This makes it tricky when a reporter finds himself writing an article about several members of the same family.
Averted in Iceland, where the patronymic last name is thought of as more a description than an actual name, honorifics are applied to the first name, and even the phone book is listed in first-name order.
Most Koreans refer to each other by title, title + surname, or a generic family term like "Auntie" or "Grandma", unless they are close, and sometimes not even then.
Additionally, addressing a Korean as "Surname + ssi" is extremely rude if they don't happen to work for you, that being how subordinates are addressed. It's also very common for Koreans to address each other by their full names, in part because almost all Korean names are only three syllables long (this last is also true in most of China, whose name-pattern Korean borrowed some time after the Three Kingdoms period).
In Holland, at least in the East region of Twente, it's not unusual for people to call them by their last name as a greeting.
As noted in Little Women, when Jo tells Laurie that she's not Miss March, she's only Miss Jo, it was a common practice in the 1800s to refer to the oldest of multiple sisters by "Miss [surname]" and all younger sisters as "Miss [first name]".
An unusual academic example: at St John's College, students refer to each other by honorific and last name in class, and often in non-academic situations, with the result that many people are ignorant of the first names of fellow students they see every day.
Dunno about other Spanish speaking countries, but in Argentina is common to have a Last Name Basis between male persons, even if they are best friends, and First Name Basis for female persons. It's also common for male persons to be addressed by a nickname that is often based on a physical attribute.
Last Name Basis is only used in the first year(s) of high school, and some particular places (some extremely vertical enterprises, the army/police forces) unless you are addressing to a professional (like a doctor) or somebody really important (Mr. President). Everyone else use their First name or his/her nickname, calling a person by their last name is considered offensive and awkward, unless that person requests it.
Longtime San Francisco TV news anchor Fred Van Amburg billed himself as just Van Amburg later in his career.