Mr. Ollivander is the owner of the wand store, Ollivanders, in Diagon Alley. It's not clear how old Mr. Ollivander is; his shop's been open since 382 B.C. He's described as "an old man… [whose] wide, pale eyes shin[e] like moons through the gloom of the shop" (5.217). Harry finds him a little intimidating, and thinks that his "silvery eyes [are] a bit creepy" (5.220).
Mr. Ollivander can remember every wand he's sold. He knows what each one was made of and to whom he sold it. He tells Harry, for example, the kinds of wands each of Harry's parents had. The materials that go into a wand and a wand's length are both important. They influence the kind of work the wand is best suited for. (For more on the significance of wand types, see our section on "Wands" in "Symbols, Imagery, Allegory.")
When it takes Harry forever to find the right wand in Mr. Ollivander's shop, Mr. Ollivander seems pleased rather than annoyed. He's invested in connecting each customer with the perfect product.