Here is the full list of all 50 LEGO Harry Potter: Years 5-7 trophies - there are 37 bronze, 10 silver, 2 gold and 1 platinum.
Collect all Trophies
Complete the game to 100% (Single Player Only)
Unlock every bad wizard (Single Player Only)
Unlock ALL of the Order of the Phoenix character variants (Single Player Only)
Defeat every Harry freeplay variant as Lord Voldemort
Unlock all witch characters (Single Player Only)
Complete the Bonus Level
Complete Year 8
Complete "The Flaw in the Plan"
Complete "Snape's Tears"
Unlock every character with a pet (Single Player Only)
Unlock all of the members of Dumbledore's Army (Single Player Only)
Complete "Fiendfyre Frenzy"
Use a Weasley box with every Weasley
Unlock every pyjama character variant (Single Player Only)
Defeat 30 Red Caps
Complete "Burning Bridges"
Defeat Bellatrix with Neville (Waiter) in a duel
Complete "Back to School"
Complete "The Thief's Downfall"
Complete Year 7
Complete "DOBBY!"
Complete "Lovegood's Lunacy"
Complete "Sword and Locket"
Unlocked on hitting 50% game completion (Single Player Only)
Complete "In Grave Danger"
Complete the scene where Hermione and Harry dance in the tent
Visit the Hogwarts Foyer in Year 7
Complete "Magic is Might"
Complete all lessons (Single Player Only)
Complete "The Seven Harrys"
Use the Deluminator
Complete Year 6
Complete "Horcrux and the Hand"
Complete "Felix Felicis"
Complete "Love Hurts"
Complete "A Not So Merry Christmas"
Complete "Just Desserts"
Collect 1 billion studs (Single Player Only)
Complete "Out of Retirement"
Complete Year 5
Complete "A Veiled Threat"
Defeat Bellatrix as any Sirius Black character variant in a duel
Complete "A Giant Virtuoso"
Complete "Kreacher Discomforts"
Complete "Focus!"
Complete "Dumbledore's Army"
Use a Quibbler dispenser 25 times
Complete "Dark Times"
Stand still with no controller input for 5 minutes