I was 3-4 years old. I had a doting grandmother that taught me how to read.
When I was in kindergarten, I would go read to the first grade classes while my classmates were working on learning how to read. So I received public speaking training early too 
Calm Kiwi
No genius here, at all. I just learned to read early because I come from a family of readers, and they read book stories to me, so it was something my young mind saw as important, and learned. This was in the sixties, so before many competing media for attention. I learned it because it was presented as worthwhile, and the little sponge mind absorbed what was presented.
In a similar manner, my sister’s son was raised with a Dad who loves video games (He’s an early on fan, a Sega expert), and, so, nephew always played video games, and could navigate them way beyond what is normally expected of a four-year old. The little guy would blow people’s minds(ten years ago) with his ability. It was simple exposure to it, with the attention of an adult who encouraged it.
I’ll add, I cannot play a video game at all; it’s too confusing to my forty-some mind. Granted, I haven’t spent much time with it, but having your young mind “wired” that way makes a huge difference. I suppose to kids now, that reading thing might seem like a one-dimensional slowpoke business.
Mom says I was 3. I don’t remember knowing how old I was, just that I had figured out how the SQUIGGLES MADE WORDS!!! I was lying on the rectangle-patterned kitchen linoleum with a Dr. Seuss book called Hop on Pop. It was awesome.
Oh good! I was so happy at reading a book with *chapters * - I think I told anyone who would listen.
Thanks for the cites.
Five
I was singled out in kindergarten and never fully recovered.
Way back then, kids in our school district learned phonics in the beginning of first grade and began to actually read sometime later that year.
Nowadays it seems like three year olds who can read are no big deal.
I don’t actually remember learning to read, but my mother claims I could read certain words by the time I was two. As she tells the story, I could look at a soup can label and say what the flavor was, or recognize car names. We had a Chevrolet, and I could apparently spot that arrangement of letters – along with Plymouth, Ford, and others – in a magazine ad, or on an older model which differed in appearance from the vehicles I saw daily.
I do remember that my kindergarten teacher got upset whenever I picked up a book in the classroom and started to read to myself. She was of the opinion that a child should be illiterate on his* first day of formal schooling, so that he’d learn the correct way to peruse written material. The fact that both of my parents had worked as teachers (Dad had majored in music education, and also taught fifth grade between stints as a band/vocal instructor, while Mom taught fourth grade before “retiring” to raise a family, as was the custom at the time) mattered not a whit to Mrs. M.
*I’d normally type “his/her”, but went the sexist route here for clarity and to reflect the prevailing usage of 1964
It is legend among my family that I was reading the backs of movie covers when I was three.
Really. Ask my parents.
I’d just like to chime in again to yes, I agree that most of us early readers were read to a lot as children. My mother and grandparents would all read me a story each every day, usually more.
I’d also agree that early reading is no real guide to later intelligence. I got average to good grades in most subjects - the only subjects I ever excelled at were English Lit and Drama, and I was (still am, actually) terrible at maths. And I was late at learning others things - I seem to remember it took me longer to learn how to tell the time, and fasten my own shoe laces than it did the other kids.
I remember being able to read my own full name (and write) at the age of four, as well as my address and telephone number. I grew up in a house full of books, my mum being an avid reader, and always encouraged to look at books. Early numeracy would have come from that telephone number (first of two for this house) and remembering the pattern of the digits. Same with words and letters. I remembered stuff – and then saw the patterns fit in. Still do that, at times.
Oh, and just to add – I was also read to a lot, up until I was about 6 years old (and then it was done spradically in school after that). But I used to read a lot of stuff to my grandma who spent the last years of her life confined to her bed, up until she died when I was 9.
My mom tells me I was 2 years and some months old when I began to read aloud to her. She says she thought I had just memorized the books because she read them aloud to me, so she handed me something else, and I read that to her.
Like many posters, I cannot recall ever not being able to read.
Oh thank goodness. I thought you were really going to try and out do me by saying that you started reading Ayn Rand Novels in your dads sack. 
He found them too juvenile.
Chad Varah, founder of the Samaritans, based his belief on re-incarnation (slightly unorthodox in itself for an Anglican priest) on the “fact” that he could read as an infant. Not, apparently (and I can vouch for this, as I heard him tell the tale on the radio) also on the fact that he could remember, as an adult, that he could read as an infant, but solely on the fact that he could read. We know this because Mr Varah’s governess/nurse imparted this information to him in later life, and why should she tell ridiculously outlandish tales? So, there we are. QED and all that.
We don’t know – I was reading before I had learned to talk. But the best guess is some time before age 2.
Now, I know some people ready early, but I’m wondering…
… just how would anyone have known you really were reading if you couldn’t talk?
Matbe he wrote them a memo?
The way I’ve heard it is, I would pick up a book, and take my time paging through it. Other kids would flip through books fast, and I was going slow enough that I clearly wasn’t just looking at the pictures.
You people have all got your priorities screwed up.
Nobody really needs a kid who can read (or look at books slowly) as a toddler. What good is that?
Now MY son, he puts his dirty dishes in the sink. At 18 months, he’d finish a bottle & walk into the kitchen - clunk! - we’d hear it land in the sink.
THAT is a useful skill.
Keep in mind that the responses in this thread are biased by a few things. One is that Dopers probably tend to be the kind of people who are smarter than average and who also really, really like to read. People who didn’t learn to read until late in life are not likely to even open a thread titled, “When did you learn to read?” and are much less likely to respond than early readers.
According to my mom’s baby diary, I was reading at around 3-3.5 years old. I remember reading the Little House on the Prairie books and Black Beauty when I was in kindergarten. I read The Red Badge of Courage when I was 5 or 6 (part of a “classic literature” book set) and didn’t really like it or get it, which is probably why I still disliked it when I had to read it again for an American literature course in university. That, or because Crane is tedious. I remember that some of my favorite reading was mythology. My parents got a subscription to story anthologies from a mail-order publishing company that featured mostly world folk-tales and myths.
I was definitely unusual in reading so early. That was the main reason I got IQ testing when I entered kindergarten. The only thing my school could do, since it was so small, was to put me in with the older kids’ reading classes. Most kids didn’t learn to read until first or second grade, at around 6-7 years old.
Early reading is not a really strong indicator of eventual academic or financial success, though, so it doesn’t matter that much. I’ll bet that at least some of the kids at my school who didn’t learn to read until 6 or so went on to get more advanced university degrees than I did, and most are probably making more money than me right now. If the kid is still having trouble at 8-10 years, then there’s a problem, but not reading at 4 is perfectly normal. Your friend’s kid will start reading when he/she’s ready to. Heck, some kids still can’t even speak in full sentences at age 4.