Being a game mascot means that Dialga has recieved TONS of figures over the years. Since there are so many I only really collect those that interest me, along with any I happen to find along the way.

Dialga Preorder Figure
Manufacturer: Kaiyodo (Japan)
Product Line: Pokémon Preorder Bonuses
Release Date: September 28 2006
Purchased From: PKMNCollectors
You could get this if you preordered Pokémon Diamond in Japan at certain stores. The tail part actually is separate from the main body and has to be attached, which I didn't know until I was cleaning it one day and it fell off, scaring me very badly.

Dialga Best Wishes Kid
Manufacturer: Bandai (Japan)
Product Line: Pokémon Kids Best Wishes ~Mewtwo Hen~
Release Date: June 11 2013
Purchased From: Pokevault
This figure has been rereleased a couple times, with this one being from the most recent release in 2013. The pose is fairly standard, but the proportions make them pretty cute.

Dialga Bottle Cap Figure
Manufacturer: Kaiyodo (Japan)
Product Line: Pokémon Figure Museum
Release Date: 2007
Purchased From: Mercari Japan
I really like this one! It would look pretty cool in a diorama of sorts that matches the rock Dialga is standing on.

Dialga Tomy Figure (New Pose, US Version)
Manufacturer: Takara Tomy (Japan)
Product Line: Monster Collection BW
Release Date: July 2011
Purchased From: Nintendo NY
This pose is a lot more interesting than the one of the original Tomy figure release. I got a second one in a lot of random figures, and at some point I want to paint it shiny. Or maybe even Primal Dialga colors, since the clear version already somewhat resembles the shiny.

Dialga Moncolle Plus Figure
Manufacturer: Takara Tomy (Japan)
Product Line: Moncolle Plus
Release Date: June 6 2009
Purchased From: PKMNCollectors
This line of figures all feature Pokémon in poses different from the standard releases, on bases that can connect them to a few different games. Kind of like Amiibo, but less versatile.

Dialga Poké Doll Figure
Manufacturer: ??? (Japan)
Product Line: ???
Release Date: ???
Purchased From: PKMNCollectors
I believe this guy was snapped off the top of a pen due to a hole in their belly. I can't get enough of them, they're so tiny and adorable!
Click here to see them compared with the real Poké Doll.

Dialga Alternate Pose Kid Figure
Manufacturer: Bandai (Japan)
Product Line: Pokémon Kids Diamond & Pearl 6
Release Date: January 31 2008
Purchased From: eBay
There are two releases of this figure, but I'm not really sure which one mine is since from what I can tell, they look exactly the same. It looks like Dialga is looking over their shoulder, or maybe yelling at Palkia for something.

Dialga Chou Get Zenkoku Version 11 Figure
Manufacturer: Bandai (Japan)
Product Line: Chou Get Taizen (Zenkoku Version 11)
Release Date: February 2010
Purchased From: PKMNCollectors
Not 100% sure I've identified this figure correctly. I think the stand is from something else, but hey, it works.

Dialga Chou Get Taizen 12 Figure
Manufacturer: Bandai (Japan)
Product Line: Chou Get Taizen (12)
Release Date: December 2007
Purchased From: PKMNCollectors
I think this pose is kinda funny. Like the roaring Dialga Kid above, there are multiple identical releases and I'm not really sure which one I have.

Palkia Tomy Figure (New Pose, US Version)
Manufacturer: Takara Tomy (Japan)
Product Line: Monster Collection BW
Release Date: July 2011
Purchased From: Nintendo NY
There is one impostor among us
But seriously, I felt kinda bad for this guy being all alone, so I put them with the Dialgas in hopes they wouldn't be as lonely.

Dialga Soap Figure
Manufacturer: ??? (Japan)
Product Line: ???
Release Date: ???
Purchased From: Mercari USA
Need to do more research on this. I've been told that you could get them randomly when melting soap bars that all came with a different figure inside, but I don't know the details.

Dialga Clear Tomy Figure
Manufacturer: Takara Tomy (Japan)
Product Line: Monster Collection DP
Release Date: July 14 2007
Purchased From: eBay
I believe this could be obtained when going to see the Darkrai movie in select theaters across Japan. They have an odd tendency to "sweat" or become slimy when left out for long enough, but keeping them inside an acrylic display case I have seems to have solved that problem.

Dialga Rolling Figure
Manufacturer: ??? (Japan)
Product Line: ???
Release Date: ???
Purchased From: PKMNCollectors
There are little wheels in the base of this that let you roll them around like a tiny car. The paint on mine's eyes is a bit off, so it look like they're winking at you.

Dialga Keychain Figure
Manufacturer: ??? (Japan)
Product Line: ???
Release Date: ???
Purchased From: PKMNCollectors
There's a hole in this Dialga's head that makes me think they were originally a keychain or strap. I should look for one that fits so I can restore their original function.

Dialga Figure on blue base
Manufacturer: ??? (Japan)
Product Line: ???
Release Date: ???
Purchased From: PKMNCollectors
Yet another figure I know absolutely nothing about! The blue base looks pretty nice, though.

2018 Dialga McDonalds Figure
Manufacturer: McDonald's (USA)
Product Line: 2018 McDonald's Pokémon Happy Meal Toys
Release Date: October 16 2018
Purchased From: PKMNCollectors
This guy was included in Happy Meals during the Legendary Pokémon promotion of 2018. I'm a vegetarian so I couldn't get one at McDonalds myself and ended up buying one secondhand.

Dialga Sukui Doll
Manufacturer: ??? (Japan)
Product Line: ???
Release Date: ???
Purchased From: PKMNCollectors
Another figure I need to do more research on. Based on the photos I've seen the color on these guys seems to be pretty inconsistent, with some even resembling the Shiny variant somewhat.

Dialga Clipping Figure
Manufacturer: Bandai (Japan)
Product Line: Pokémon Clipping Figures
Release Date: April 2007
Purchased From: PKMNCollectors
This figure uses a pretty unique pose compared to many of the others. Dialga looks to be sulking here.....wonder what they're thinking about.

Dialga DX Kid Figure
Manufacturer: Bandai (Japan)
Product Line: Pokémon Kids DX (Diamond & Pearl 2)
Release Date: August 2007
Purchased From: PKMNCollectors
This guy is bigger than a normal Kid, and also poseable! They look kind of silly though.

Dialga 2022 Kid Figure
Manufacturer: Bandai (Japan)
Product Line: Pokémon Kids (Dialga & Palkia & Arceus Hen)
Release Date: February 2022
Purchased From: Discord
Dialga's newest Kid figure as of right now. This is the first one where they're more hunched over and nervous looking as opposed to the previous versions.

Dialga Clear Tomy Figure (New Pose)
Manufacturer: Takara Tomy (Japan)
Product Line: Monster Collection DP
Release Date: July 18 2009
Purchased From: Mercari Japan