One fairly obvious answer of who the richest wizard is might be Bellatrix Lestrange, as in Harry Potter and the Deathly Hallows, we can see how much stuff she has in her vault. However the true answer is shown all the way back in the Philosophiser's Stone (or the Sorcerer's Stone for Americans), and that is the Philosopher himself- Nicolas Flamel. In chapter 13 of the book, Harry, Hermione and Ron complete their search for any mention of Flamel in the library, finding a book that tells them all about him.

“Nicolas Flamel,” [Hermione] whispered dramatically, “is the only known maker of the Philosopher's Stone!”

And later on in the chapter:

 The ancient study of **alchemy** is concerned with making the **Philosopher’s Stone**, a legendary substance with astonishing powers. The stone will **transform any metal into pure gold**. It also produces the **Elixir of Life**, which will make the drinker immortal. There have been many reports of the **Philosopher’s Stone** over the centuries, but the only Stone currently in existence belongs to **Mr. Nicolas Flamel**, who celebrated his six hundred and sixty-fifth birthday last year, enjoys a quiet life in Devon with his wife, Perenelle (six hundred and fifty-eight).

The fact that the stone will transform any metal into pure gold makes it obvious that as he is the only living owner of a philosopher's stone, he is likely the richest.

Here's some more info about Flamel and his journey to making the stone: https://www.wizardingworld.com/features/the-real-nicolas-flamel-and-the-philosophers-stone

One fairly obvious answer of who the richest wizard is might be Bellatrix Lestrange, as in Harry Potter and the Deathly Hallows, we can see how much stuff she has in her vault. However the true answer is shown all the way back in the Philosophiser's Stone (or the Sorcerer's Stone for Americans), and that is the Philosopher himself- Nicolas Flamel. In chapter 13 of the book, Harry, Hermione and Ron complete their search for any mention of Flamel in the library, finding a book that tells them all about him.

“Nicolas Flamel,” [Hermione] whispered dramatically, “is the only known maker of the Philosopher's Stone!”

And later on in the chapter:

The ancient study of alchemy is concerned with making the Philosopher’s Stone, a legendary substance with astonishing powers. The stone will transform any metal into pure gold. It also produces the Elixir of Life, which will make the drinker immortal. There have been many reports of the Philosopher’s Stone over the centuries, but the only Stone currently in existence belongs to Mr. Nicolas Flamel, who celebrated his six hundred and sixty-fifth birthday last year, enjoys a quiet life in Devon with his wife, Perenelle (six hundred and fifty-eight).

The fact that the stone will transform any metal into pure gold makes it obvious that as he is the only living owner of a philosopher's stone, he is likely the richest.

Here's some more info about Flamel and his journey to making the stone: https://www.wizardingworld.com/features/the-real-nicolas-flamel-and-the-philosophers-stone

One fairly obvious answer of who the richest wizard is might be Bellatrix Lestrange, as in Harry Potter and the Deathly Hallows, we can see how much stuff she has in her vault. However the true answer is shown all the way back in the Philosophiser's Stone (or the Sorcerer's Stone for Americans), and that is the Philosopher himself- Nicolas Flamel. In chapter 13 of the book, Harry, Hermione and Ron complete their search for any mention of Flamel in the library, finding a book that tells them all about him.

“Nicolas Flamel,” [Hermione] whispered dramatically, “is the only known maker of the Philosopher's Stone!”

And later on in the chapter:

 The ancient study of **alchemy** is concerned with making the **Philosopher’s Stone**, a legendary substance with astonishing powers. The stone will **transform any metal into pure gold**. It also produces the **Elixir of Life**, which will make the drinker immortal. There have been many reports of the **Philosopher’s Stone** over the centuries, but the only Stone currently in existence belongs to **Mr. Nicolas Flamel**, who celebrated his six hundred and sixty-fifth birthday last year, enjoys a quiet life in Devon with his wife, Perenelle (six hundred and fifty-eight).

The fact that the stone will transform any metal into pure gold makes it obvious that as he is the only living owner of a philosopher's stone, he is likely the richest.

Here is a list of the top 12 richest wizards: https://screenrant.com/richest-harry-potter-characters-ranked-by-wealth/#bellatrix-lestrange

And some more info about Flamel and his journey to making the stone: https://www.wizardingworld.com/features/the-real-nicolas-flamel-and-the-philosophers-stone

One fairly obvious answer of who the richest wizard is might be Bellatrix Lestrange, as in Harry Potter and the Deathly Hallows, we can see how much stuff she has in her vault. However the true answer is shown all the way back in the Philosophiser's Stone (or the Sorcerer's Stone for Americans), and that is the Philosopher himself- Nicolas Flamel. In chapter 13 of the book, Harry, Hermione and Ron complete their search for any mention of Flamel in the library, finding a book that tells them all about him.

“Nicolas Flamel,” [Hermione] whispered dramatically, “is the only known maker of the Philosopher's Stone!”

And later on in the chapter:

 The ancient study of **alchemy** is concerned with making the **Philosopher’s Stone**, a legendary substance with astonishing powers. The stone will **transform any metal into pure gold**. It also produces the **Elixir of Life**, which will make the drinker immortal. There have been many reports of the **Philosopher’s Stone** over the centuries, but the only Stone currently in existence belongs to **Mr. Nicolas Flamel**, who celebrated his six hundred and sixty-fifth birthday last year, enjoys a quiet life in Devon with his wife, Perenelle (six hundred and fifty-eight).

The fact that the stone will transform any metal into pure gold makes it obvious that as he is the only living owner of a philosopher's stone, he is likely the richest.

Here's some more info about Flamel and his journey to making the stone: https://www.wizardingworld.com/features/the-real-nicolas-flamel-and-the-philosophers-stone