After much hunting and diligent editing, here is every Hitchcock cameo ever spotted from his beginning in silent cinema to his graphic horror in the 70s. If you can't spot him in the video, I've made a handy guide for each clip you see.
Watching guide:
The Lodger: A Story of London Fog 2 cameos! Clip 1: The man shouting into the phone in the bottom center, Clip 2: in the middle of the crowd with the fake beard
Easy Virtue walking with a cane on the right
Blackmail sitting on the left being harassed by a child (one of his longest cameos)
Murder! walking across the shot from left to right
The 39 Steps walking to the right and tossing a piece of paper on the ground
Young and Innocent to the left fiddling with a camera (another of Hitchcock's longest)
The Lady Vanishes walking to the left smoking a cigar and shrugging his shoulders
Rebecca in the background walking to the left wearing a bowler hat
Foreign Correspondent reading a newspaper on the left
Mr. and Mrs. Smith walking from left to right as the camera pulls out
Suspicion 2 cameos! clip 1: leading the horse, clip 2: mailing a letter in the background
Saboteur top left corner under the light bulb
Shadow of a Doubt playing cards with the doctor
Lifeboat in the ad for Reduco "the obesity slayer"
Spellbound leaving the elevator smoking a cigar and carrying a violin case
Notorious drinking champagne
The Paradine Case on the right, smoking a cigar and carrying a cello case
Rope walking on the sidewalk in a blue suit and holding a newspaper
Under Capricorn 2 cameos! clip 1 in a blue suit, brown pants and top hat in the middle of the frame, clip 2 same outfit in the middle of a group of 3 people
Stage Fright on the right turning and looking at the main character
Strangers on a Train boarding the train with a stand up bass
I Confess walking across the horizon
Dial M for Murder sitting at the table in the picture
Rear Window winding the clock in the piano player's apartment
To Catch a Thief Sitting on the right in the bus
The Trouble With Harry walking on the left in a trench coat
The Man Who Knew Too Much standing the bottom left of the crowd
The Wrong Man This cameo is different. Because The Wrong Man is based on the experiences of a real person Hitchcock wanted to approach the whole thing differently.
Vertigo walking from left to right carrying a trumpet case
North By Northwest failing to catch a bus
Psycho in the window wearing a cowboy hat
The Birds walking his reallife dogs out of the pet shop
Marnie exiting a room on the left and looking directly at the camera
Torn Curtain holding a small child on his knee
Topaz sitting in a wheelchair and then standing up to shake hands with someone
Frenzy 2 cameos! clip1: in the middle of the crowd wearing a bowler hat, clip 2 same hat in the bottom center
Family Plot silhouette seen in in the window of Registrar of Births & Deaths