Metal Gear Solid is a franchise known for its ability to create compelling characters, from its protagonists to its villains. The series' best character work is found in Metal Gear Solid 3, as it introduced fans to likes of The Boss and EVA while it added depth to existing characters like Ocelot, and Metal Gear villain Big Boss.
As to be expected with a Hideo Kojima game, the characters are all very detailed. However, not all of the information about every MGS3 character can be found easily. That's the point of this list, as it provides data for the main (and a few secondary) characters of the game, without the need for you to search all over for it yourself.
10 Sigint
Weapons expert Sigint (real name Donald Anderson) was a member of Fox and was on Snake's mission support team for Operation Snake Eater. He was born on November 11, 1939, which means he would've been 24 during the events of Metal Gear Solid 3.
MGS3 claims he stands at 6" (and five-eighths of an inch to be exact) tall, although in the third game you only got to see this for yourself right at the end, when he's there to show support for Snake who's being given the title of Big Boss, the rest of the time you communicate with him through radio.
9 Para-Medic
Another member of the Operation Snake Eater mission support team was Para-Medic (commonly referred to as Dr. Clark in other games in the series). Her job was to provide Snake with medical advice as well as information on what he could and couldn't eat while in the jungle.
She was born on June 22, 1936, in Boston Massachusetts, making her 28 years old during Operation Snake Eater. Standing at 5'5" makes her the shortest member of Snake's support team, although she is still around average height for a woman.
8 Granin
Granin is really important to the Metal Gear story, as he was the one who came up with the concept of a Metal Gear. In MGS3 though, he spends most of his time drinking in his office, bitter that Colonel Volgin chose Sokolov's idea over his (at least he has nice shoes).
His exact birthday is unknown as the developers have never revealed it, although the voice casting sheet for MGS3 states he is in his 60s during the events of the game, so he'd have to have been born between 1895 and 1904. His height is also not divulged, however he's visibly a few inches shorter than Snake, meaning he must be around 6" or 6'1".
7 Major Zero
Major Zero was the Commanding Officer of the mission support team and Snake for both the Virtuous Mission and Operation Snake Eater. He was born on August 12, 1909, and he turned 55 just before the events of Metal Gear Solid 3. Despite his age, he still manages to outlive almost everyone on this list.
Interestingly, Zero is the exact same height as Sigint at 6" and five-eights of an inch. Also like Sigint, there were minimal opportunities to see the Major in the flesh over the course of the game.
6 Sokolov
During the Virtuous Mission, Sokolov was captured by Colonel Volgin and forced to develop the Shagohad, which is a nuclear-armed tank he invented. Following that, Snake was tasked with saving the scientist as a part of Operation Snake Eater (something he failed to do in the Virtuous Mission).
Like his fellow weapons scientist Granin, Sokolov's exact details have never been revealed. The voice casting sheet reveals he's in his 50s during Metal Gear Solid 3, which means he was born between the years of 1905-1914. As for his height, Sokolov was shown to be as tall as Snake (perhaps even a little taller), making the scientist 6'3" or 6'4".
5 EVA
EVA was one of Snake's most useful allies throughout Operation Snake Eater. She was a spy who was usually very secretive, yet for some reason, all her details (except her actual name, which is never revealed in the series) were readily available from Snake's radio.
During Operation Snake Eater, she was 28 years old, having been born on May 15, 1936. Any fans of the series might be interested to know that means she was 35 or 36 (depending on the month) when she gave birth to Solid and Liquid Snake. At 5'10" and a quarter of an inch, she is one of the shorter main characters in the game, yet she is still the tallest female on this list (just).
4 Colonel Volgin
Volgin was the leader of the GRU and the evilest villain of the game. While the game's other antagonists showed slithers of humanity, he was a true monster.
This is another instance where the voice casting sheet comes in handy as it states that Volgin was in his 50s during Metal Gear Solid 3, which means his year of birth was sometime between 1905 and 1914. Unsurprisingly, Volgin towers over everyone else on this list as he stands at a staggering 6'7". He doesn't need his lightening to be intimidating, as his size alone would terrify most people.
3 Ocelot
As with any Metal Gear Solid game, you don't find out Ocelot's true intentions in MGS3 until the end. Prior to the ending, he acts as a secondary antagonist as he tries desperately to defeat Snake one on one.
Also towards the end, The Boss tells a story of how she once gave birth to a boy, and if you have a certain call with EVA earlier in the game, you can deduce that Ocelot is that boy. The story reveals that The Boss gave birth to Ocelot on the battlefield during the Allied invasion of Normandy on June 6, 1944, meaning he was only 20 during Metal Gear Solid 3. He grew to be slightly taller than his mother at 5'11".
2 The Boss
The Boss was a legendary hero, mentor to Naked Snake, and the final boss in Metal Gear Solid 3. Snake's radio had little personal data on her, as the likes of her age and birthday were excluded from it. Luckily, the Metal Gear Solid 4 database has a timeline that shows she was born in 1922 (although there is no exact day), thus during the game, she would've been 41 or 42 depending on if she'd already had a birthday that year.
One piece of information about The Boss that Snake's radio did include was her height. Earlier it was mentioned that EVA was the tallest female on the list at 5'10" and a quarter of an inch, well The Boss comes very close at exactly 5'10".
1 Naked Snake
Naked Snake's personality and actions in Metal Gear Solid 3 turned him into a legend, both inside the universe of Metal Gear Solid and in the real-life gaming industry. Despite being the protagonist and an iconic character, there is not a lot known about his birth, except that he was born in 1935.
There is a bit of contention around Naked Snake's height, as in Metal Gear 2: Solid Snake he's labeled as 5'10", whereas Metal Gear Solid identifies him as 6'3". The Metal Gear Solid number seems to be the correct one though, as if he was 5'10" he'd be virtually the same height as EVA, and in MGS3 he's visibly a few inches taller than her.