A former circus strongman, he is MI6' head of Station T in Istanbul. He is a wise, good natured man whom Bond immediately takes a liking to.
Adaptation Name Change: His given name was changed from "Darko" to "Ali" in the film, possibly because the context of "Darko" (it's exactly what you think it is) would be uncomfortable even for 1963.
Abusive Parents: We get to learn his rather twisted backstory in the book. His father was a brutish man who stole other men's wives and thrashed his kids for discipline. Nevertheless his community respected him (as does Kerim in an odd way) due to being a poor village that prized strength.
The Patriarch: Exclusively employs family members, reasoning they're the only people you can trust in the spying business. This, of course, has the side effect of him being at least as promiscuous as Bond is.
Unscrupulous Hero: He's sexist, hedonistic, and willing to do all sorts of dubiously-moral deeds, but is also the most loyal and competent intelligence agent in Turkey. Bond would later encounter similar "bad good guy" characters such as Marc-Ange Draco and Tiger Tanaka.
Tatiana "Tanya" Romanova
Played by: Daniela Bianchi
A corporal in Soviet Army Intelligence, assigned to work in the Soviet Embassy in Istanbul as a cipher clerk. Because of her beauty, Rosa Klebb assigns her the mission of seducing Bond and having him take her to England to deliver a LEKTOR code machine.
Bond: [checking her out via the periscope] Well from this angle, things are shaping up nicely.
Donald "Red" Grant
Played by: Robert Shaw
Along with Oddjob and Jaws, he is quite an iconic Bond villain henchman. Grant is a tall, burly, blonde SPECTRE agent (SMERSH in the books) and a sadistic, ruthless and psychotic killer. Grant's backstory in the movie and book are completely different but both effectively amount to "This is a horrible person you don't want to mess with".
Bond Villain Stupidity: Robert Shaw's chilling, brilliant performance obscures the fact that Grant may be the single most egregious example in the entire series. For once, shooting Bond is the actual plan, but Grant manages to muck it up with an inexcusable bout of Evil Gloating and Just Between You and Me. Further, after revealing to Bond that he's going to kill him and Tatiana and make it look like Bond committed murder-suicide, Grant gloats, "The first one [bullet] won't kill you. Not the second. Not even the third. Not till you crawl over here and kiss my foot!" Of course, if Grant had succeeded in doing this, with four or more bullets in Bond's dead body, it wouldn't look like a suicide.
Dumb Blonde: Subverted. While the book version doesn't seem like the sharpest tool in the shed, he's actually able to do things that other Bond villain henchmen are completely incapable of (like use stealth or hold down a cover).
The Dragon: Rosa Klebb's or Blofeld's in the movie, and General G's in the book.
Made of Iron: Doesn't flinch when hit by a pair of brass knuckles. This is a slight exaggeration from the book, where he doubles over slightly and stands upright again from a blow that the narration notes would have left any normal man cringing on the floor.
Mr. Fanservice: Practically alone amongst male Bond villains, Grant is actually incredibly handsome. The novel notes, however, that he's handsome in such a way that you can still tell there's something... off about him.
Psycho for Hire: A serial killer (stemming from advanced case of manic-depressive disorder) in the original book, and a homicidal paranoiac in the movie.
The Quiet One: Bordering on The Voiceless. He does not speak for most of the movie, and when he finally does, it's to imitate someone he has just murdered.
Red Right Hand: He's asexual. More literally, his reddish skin tone is noted in the novel as marring what are otherwise extremely handsome physical features, giving a clue to his nature.
Sadist: As shown with the aforementioned "Kiss my foot!" line and, if you look closely, you can see a smile on his face as he prepares to use his garrote on Bond.
In the movie, Rosa Klebb is depicted as a former SMERSH agent who has defected to become a member of SPECTRE (Blofeld refers to her as "Number 3"). She uses Kronsteen's plans to obtain the Lektor and kill Bond. She deceives Tatiana Romanova into helping Bond steal the Lektor, and then sends Red Grant to kill Bond and recover it.
The head of planning for SPECTRE. He devised a plan to lure James Bond into Turkey and then kill him, humiliating the British government and getting revenge for the death of Dr. No. When the plan failed, he was killed with a poison-tipped knife concealed in a shoe.
Adaptational Villainy: He's not a nice man in the book, but he's still just a Soviet Colonel doing his job. The film makes him into a board member for the world's most powerful terrorism-for-hire organization and gives him about a million levels in smug.
Even Evil Has Loves Ones: Averted, actually; it's mentioned that he has a wife and children in the book, but his years as a merciless Soviet intelligence agent has left him unable to see them, or anyone, really, as anything other than pieces on a chessboard.
Evil Genius: The mastermind behind the lektor decoder plot.
No Name Given: Subverted and played straight; Number One is identified as "Ernst Blofeld" in the closing credits, but the audience during the initial run of the film is only given a "?" when presented with the identity of the actor.
You Look Familiar: Not so much as look familiar (since we never see his face), but the actor who plays him is Anthony Dawson, who appeared in Dr. No as Professor Dent. Not that the audience would know as Dawson is not seen, heard or credited.