Season 4
* = Episode Download Available
60. Parents Day *
61. Eugene's Birthday/ Stinky's Pumpkin *
62. Dinner for Four/ Phoebe Skips *
63. Full Moon/ Student Teacher *
64. Big Gino/ Jamie O. In Love *
65. The Beeper Queen/ Oskar Can't Read? *
66. Friday the 13th/ Headless Cabbie *
67. Helga's Parrot/ Chocolate Turtles *
68. Love and Cheese/ Weighing Harold *
69. It Girl/ Deconstructing Arnold *
70. Grudge Match/ Polishing Rhonda *
71. Veterans Day *
72. Back to School/ Egg Story *
73. Weird Cousin/ Baby Oskar *
74. Helga Sleepwalks/ Fighting Families *
75. Monkeyman! / Buses, Bikes and Subways *
76. Grandpa's Sister/ Synchronized Swimming *
77. Helga's Masquerade / Mr. Green Runs *
78. Helga on the Couch *
79. Dino Checks Out *
~Back~
  The fourth season of Hey Arnold! began on March 10, 1999, with new episodes running Monday & Wednesday nights.  ("School Play" was shown March 8, but it is considered a third season episode.)

Season 4 Notes

  * Spencer Klein replaces Phillip Van Dyke as the (third) voice of Arnold
    * The theme song has been redone, although it's the same melody and the same opening animation (and Helga still says "Move it, football head!"); this is the second Nicktoon to do this (Rocko's Modern Life had its theme song redone after its first season)
    * Speaking of the opening, if you watch carefully, one scene has changed; when Helga says "Arnold" while standing behind the large "ARNOLD" on the ground, it's no longer drawn as if she's stretching it out
    * Storyboard and Animation Directors are now listed with titles in each episode's opening credits
    * Although "School Play" was shown at the beginning of the block of new episodes, it was made as a third season episode (and it has Phillip Van Dyke as Arnold), so it is listed in the third season episode list