Dr. Wondertainment’s Interdimensional Line and Lure (SCP Foundation)
Backroom Keys (The Backrooms)
Flame Keepers’ Circle Soldiers Esoterica (Ben 10)
Gwen Tennyson (Ben 10) going to Ledgerdomain the realm of magic.
Chronosapiens (Ben 10 Series) like Clockwork can travel between Dimensions.
Catbug (Bravest Warriors) midway through jumping into the See-Through Zone.
As a Archai, Tyler Michaels (Charmed comic) has the ability to create portals to other worlds, dimensions or planes by burning holes in reality.
The Fenton Ghost Portal (Danny Phantom) allows access to the Ghost Zone.
The Infi-Map (Danny Phantom) can travel between the Ghost Zone and the Human World.
Wulf (Danny Phantom) can use his claws to rip open portals between Earth and the Ghost Zone.
Zandora's Box (Dungeons & Dragons: The Animation) can lead to any possible and impossible dimension, depending on where its opened.
Breach (Generator Rex) using her extra arms to open dimensional portals.
Grim (The Grim Adventures of Billy and Mandy) can use his scythe to slash open dimensional portals.
The Dimensional Scissors (Star vs. the Forces of Evil) are magical scissors that can cut open portals to other dimensions.
Hekapoo (Star vs. the Forces of Evil) the creator of the dimensional scissors.
Interdimensional Portal (The Jimmy Timmy Power Hour III: The Jerkinators!)
Porta-Portal (The Jimmy Timmy Power Hour III: The Jerkinators!)
Uncle Grandpa (Uncle Grandpa), among many other amazing abilities, can travel through various dimensions and planes of existence, and can even travel into other cartoon-universes as seen in the "Steven Universe" crossover.
The Magical Watches (Winx Club) can open portals to the World of Dreams/Neverland.
Dimensional Travel Watch (Marvel Comics) allow the Web-Warriors to travel between the various dimensions.
Combo Man (Marvel Comics) possesses The Century's dimensional travel.
America Chavez (Marvel Comics)
The Heart of Etheria (She-Ra and the Princesses of Power) can transport entire planets to other dimensions.
Raven (Teen Titians)
Angstrom Levy (Image Comics/Invincible)
Master of Games (Teen Titans)
Like other Speed Force conducts, Wally West (DC Comics) are able to travel through dimension breaches.
A Mother Box (DC Comics) can open powerful Boom Tubes that can allow it users to travel between galaxies, dimensions, and alternate realities.
The Sorcerer, The Sorceress, and Evil Julian (Randy Cunningham: 9th Grade Ninja) can either unit their powers or independently create a portal that leads to the Land of Shadows where the Chaos Pearls originated from.
Null Void Projector (Ben 10) is a device that can opens an portal to the Null Void.
Maltruant (Ben 10 series)
Monsters use closet doors to enter the Human World (Monsters, Inc.).
Vyod (The Incredibles)
Willow Rosenberg (Buffy the Vampire Slayer) can open dimensional portals.
Voyd (The Incredibles 2)
With his Hoverchair and powers from Edwin Gauss, DeVoe (The Flash) can travel to pocket dimensions.
Jetfire (Transformers: Revenge of the Fallen)
Sentinel Prime (Transformers: Dark of the Moon)
Wardrobe (The Chronicles of Narnia)
Shinobu Negero (Buso Renkin) using his Secret Trail to cut open a pathway to another dimension that only his DNA can enter, and hide within.
Road Kamelot (D.Gray-man) can create a doorway that can travel between dimensions.
Mastemon (Digimon) can freely open portals across space-time.
By using Instant Transmission, Son Goku (Dragon Ball series) can shift freely between Earth and the Other World.