Spencer klein
Spencer and Anndi

Spencer and Anndi McAfee in a photoshoot.

Spencer Klein (born August 31, 1986) is an American musician and former child voice actor who provided the voice of Arnold for Season 4, most of Season 5, and the theatrical film.

He is often considered by fans to be the best/most memorable Arnold voice actor, since he is the one that lasted the longest, with a total of 40 out of the original series' 103 half-hours (counting the movie as three).
The Arnolds

Arnold's voice actors (from left to right); Toran Caudell, Phillip Van Dyke, Spencer Klein

Voice Credits

# Episode Credits
61 Eugene's Birthday / Stinky's Pumpkin Arnold
62 Dinner for Four / Phoebe Skips Arnold
63 Full Moon / Student Teacher Arnold
64 Big Gino / Jamie O in Love Arnold
65 The Beeper Queen / Oskar Can't Read? Arnold
66 Headless Cabbie / Friday the 13th Arnold
67 Helga's Parrot / Chocolate Turtles Arnold
68 Love and Cheese / Weighing Harold Arnold
69 It Girl / Deconstructing Arnold Arnold
70 Grudge Match / Polishing Rhonda Arnold
71 Veterans Day Arnold
72 Back to School / Egg Story Arnold
73 Weird Cousin / Baby Oskar Arnold
74 Helga Sleepwalks / Fighting Families Arnold
75 Monkeyman! / Buses, Bikes, and Subways Arnold
76 Grandpa's Sister / Synchronized Swimming Arnold
77 Helga's Masquerade / Mr. Green Runs Arnold
78 Helga on the Couch Arnold
79 Dino Checks Out Arnold
80 Summer Love Arnold
81 Sid the Vampire Slayer / Big Sis Arnold
82 Gerald's Game / Fishing Trip Arnold
83 Bag of Money / Principal Simmons Arnold
84 New Bully on the Block / Phoebe Breaks a Leg Arnold
85 Stuck in a Tree / Rhonda Goes Broke Arnold
86 Helga's Locket / Sid and Germs Arnold
87 Beaned / Old Iron Man Arnold
88 Ghost Bride / Gerald vs. Jamie O Arnold
89 Suspended / Ernie in Love Arnold
90 Arnold Visits Arnie / Chocolate Boy Arnold
91 Harold vs. Patty / Rich Guy Arnold
92 The Racing Mule / Curly's Girl Arnold
93 On the Lam / Family Man Arnold
94 Phoebe's Little Problem / Grandpa's Packard Arnold
95 A Day in the Life of a Classroom / Big Bob's Crisis Arnold
96 Married Arnold
97 Timberly Loves Arnold / Eugene, Eugene! Arnold
Film Hey Arnold! The Movie Arnold

Other Credits

# Episode Credits
84 New Bully on the Block / Phoebe Breaks a Leg Special Thanks (as "Spencer")