I was recently looking for a count of how many legendary cards there are in Hearthstone, and I couldn’t find any answers, so I may as well make my own count. This will become current early June 2019, as this will include the neutral legendary minion SN1P-SN4P, which will be added then. If you notice I messed up then let me know (as if anyone would bother redoing this count).
WILD
Spells
There are _9 legendary quests, one per class.
Heroes
There are 9 hero transformations, One per class
Weapons
There are 9 legendary weapons, one per class.
Minions
There are 64 legendary class minions. 7 for each class, except for Hunter, which has 8.
There are 84 legendary neutral minions.
STANDARD
Spells
There are 9 legendary spells, one per class
Heroes
There are 3 hero transformations, one for Hunter, Shaman, and Warrior.
Weapons
There are 0 legendary weapons.
Minions
There are 69 legendary minions. 8 for every class except Hunter, Shaman, and Warrior, which have 7 each.
There are 51 legendary neutral minions.
WILD - PER SET
Hall of Fame
There are 7 legendary neutral minions.
Curse of Naxxramas
There are 6 legendary neutral minions.
Goblins vs Gnomes
There are 9 legendary class minions, one per class.
There are 11 legendary neutral minions.
Blackrock Mountain
There are 5 legendary neutral minions.
The Grand Tournament
There are 10 legendary class minions. One per class, except for Hunter, which has 2.
There are 10 legendary neutral minions.
The League of Explorers
There are 5 legendary neutral minions.
Whispers of the Old Gods
There are 9 legendary class minions, one per class.
There are 11 legendary neutral minions.
One Night in Karazhan
There are 5 legendary neutral minions.
Mean Streets of Gadgetzan
There are 9 legendary class minions, one per class.
There are 11 legendary neutral minions.
Journey to Un’Goro
There are 9 legendary spells, one per class. All are quests.
There are 9 legendary class minions, one per class.
There are 5 legendary neutral minions.
Knights of the Frozen Throne
There are 9 hero transformations, one per class.
There are 9 legendary class minions, one per class.
There are 5 legendary neutral minions.
Kobolds and Catacombs
There are 9 legendary weapons, one per class.
There are 9 legendary class minions, one per class.
There are 4 legendary neutral minions.
STANDARD - BY SET
Classic
There are 9 legendary class minions, one per class.
There are 14 legendary neutral minions.
The Witchwood
There is 1 hero transformation, which is a Shaman card.
There are 7 legendary class minions. Two per class, except Shaman with one.
There are 3 legendary neutral minions.
The Boomsday Project
There is 1 hero transformation, which is a Warrior card.
There are 9 legendary spells, one per class.
There are 8 legendary class minions. One per class, except Warrior with zero.
There are 5 legendary neutral minions.
Rakhastan’s Rumble
There is 1 hero transformation, which is a Hunter card.
There are 7 legendary class minions. One per class, except Hunter with one.
There are 5 legendary neutral minions.
Rise of Shadows
There are 18 legendary class minions, two per class.
There are 6 legendary neutral minions.
TOTALS
Spells
There are 18 legendary spells, two per class. 9 of these, (one per class), is a quest, meaning there are 9 quests.
Heroes
There are 12 hero transformations. One per class, except for Hunter, Shaman, and Warrior, with two each.
Weapons
There are 9 legendary weapons, one per class.
Minions
There are 133 legendary class minions. 15 for each class except for Shaman and Warrior, which each have 14.
There are 135 legendary neutral minions.
There are 269 legendary minions total, and 308 total legendary cards.
I really hope this helps at least one person other than me.