United Kingdom
This section is trying to stay limited to England, Scotland, Northern Ireland & Wales, though it's likely that Australia, Canada, Ireland and other countries with ties to England may have some of these items pop up here and there. 
This section is always being expanded, I am interested in hearing any information not yet seen here about Jem in other countries, from either if the cartoon was aired there, to what products were available.  Feel free to contact me with any of this information!

The Show: First run of the show ended on the "Britrock" episode.  It was rerun later in the 1990's with the 3rd year Stingers episodes.
Advertisement  from an Argos catalogue.
Hasbro's Core Toyline:  UK packaging is very similar to the US packaging, the only different thing about UK packaging is in the bottom right hand corner of the back of the box it has an address, instead of saying Pawtucket, RI 02862, it says, Hasbro Industries (UK) Ltd, Wokingham, Berkshire. 
What was sold in UK packaging: Presumably the entire 1986 line, plus most of the 1987 line, and one very glaring exception, Jetta!  A few other items weren't available there besides her. 
The following items are mentioned in the Hasbro UK 1987 catalogue which implies that they were intended to be marketed there, but some items may not have been picked up by distributors.  The photos are almost completely different from the ones in the American dealers catalogue and have some interesting little variants (which I'm sure are only proto-type related & not marketed).
FeaturedMissing 
Books, tapes & sets
Little Owl Superstars
Slightly larger than the mini-world books and with hard covers.  "Little Owl Superstars feature children's favourite characters from television and toyland in exciting, easy-to-read stories."  Other than Jem books, there were some made for the Wuzzles, My Little Pony, Ghostbusters and others.
Tempo Talking Stories
They were sold as book and tape sets, and possibly extra books could have been sold on their own, and apparently tapes alone may have been sold, with a different story on each side, so far it seems these can be distinguished by NOT being "Multi-voiced recordings" and having two stories per tape.  The books are very small soft covers, with great stories, awful art (though it is growing on me.)  The books are published by World International.  You may also recognize Tempo as being the same company that put out the UK videos.  Tapes are labelled w/"Multi-voiced Recording" (as well as the title, etc.)
Miscellaneous Tempo Cassette Tapes
  • "Jem's New Adventures" Double cassette, by Tempo. These stories were all featured in the 1987 Jem Annual.  They were not sold with the annual.  The cassettes are marked as "Twin Cassettes Jem"  
  • Marbo - The Rock Movie
  • Stage Management
  • Two Timing
  • Rocking Roadsters
  • A Cat Called Lucky/Super Scoop Snoop tapeProbably was not sold with the books of the same names.  I don't know where this tape fits in, but my guess is there was an earlier "tempo twin" set with these two and the other two Tempo Talking Stories on the other tape.
Jem Annuals
The Jem annuals are most closely associated with the Tempo Talking Stories, as the art is basically the same.  As well, some of the 1987 annual stories were narrated and sold separately (see above box) as Tempo's "Jem's New Adventures." 

  • In the Beginning
  • Stage Management
  • Marbo!- The Rock Movie!
  • Two-Timing
  • Desperately Seeking Synergy
  • Rockin' Roadsters
  • The Beat Goes On
  • Higher And Higher!
  • A Message From Mr Raymond
  • Night Of The Dolphins
  • Queen For A Day
  • She's A Natural
  • Prince Rat
  • Playing With Fire
  • Two Kinds Of Courage
  • Gold Gets Going
Activity and Colouring Books, Comics
Mini Activity Storybooks
Are closely related to the Talking Tempo books, the same publisher and the same size.  They have a storyline, are black and white inside and are meant to be coloured or have puzzles done in them.
The following one may not have a storyline, given it's title:
World International Activity & Colouring Books
They are the standard 8 X 11 size, except for the play pad which is about half the size.
Jem Comics
Now have their own section!

The following are not Hasbro's products, but are licensed by Hasbro and made by UK companies:

Other Jem Items
  • Picture Soap (Grosvenor)- Dated 1986. It is basically one cake of soap with a clear sticker of Jem on it, boxed with a white plastic tray.
  • View Master Reels- slightly different from US version.  Background on package is all orange, not pink.  Reels themselves also have different graphics (not sure if story and pictures are different)
  • Jemstar Earrings of dubious origin.  (they look to be for pierced ears, or clip ons, they aren't really children's items) I've seen a pair of these earrings on eBay.  They looked pretty cheap to me and didn't have any markings on them whatsoever.  The woman selling them told me they originally came in a small box with the Jem logo on it.  Why didn't they sell these over here?  They would have been huge I think.
  • Jem trinket box  I didn't get much info on this. A friend who lives there said she saw a small trinket box with pictures of Jem and the Holograms on it.
  • Jem Wallpaper (Playmates) Black background, box art.  I love this!
  • Jem Lunchbox &Thermos (Bluebird); pink with tri-colour design printed on it (not a paper label)
  • Jem briefcase It's hard plastic and briefcase sized with a nylon shoulder strap.
  • Jem Note Book (Copywrite Stationery Ltd, 1986) about 4" X 7", features Kimber box art on the back.  
  • Exercise Book (Copywrite Stationery Ltd, 1986) About 6" X 8", Features the "holograms" box art on the back. 
  • Jem Stationery Set (only have photo of the pencil atm); Dated 1986, Hasbro.  (Some info from Gina:  "That pencil came with a pink plastic pencil case with jem (herself) infront of the rocking roadster. a small white rubber (eraser) with jem logo on. and a 15cm long white ruler with jem logo sticker running down the middle.") Most likely also made by Copywrite Stationery. 
  • Jem Stationery Set #2: Paper, envelopes (back); these would have come in sets, possibly with the address book, exercise book, etc. Thanks to Lorna for these photos and info!
  • Jem vinyl handbag; Made by "Bags of character" Frankel & Roth (international) ltd/ Made in china. It is dated 1986 under the Jem logo.  Thanks to Isabelle for this photo and information.
  • Boxed 200 pc Puzzles (Milton Bradley) 

UK home videos
Were typically sold in plastic clamshell style cases with a single folded sheet behind clear plastic protective cover.  There were a few with plain cardboard covers.  Dates range from 1986 until 1991.
 
Title Episodes Included date Distributor other
Truly Outrageous The first five 1986 AMT Video Gems/Multiple Sound Distributors Ltd (aka Tempo) Features re-drawn art, front and back, very nice package IMHO! Also features a Jemstar point. 90 minutes.
Glitter n' Gold Glitter & Gold and Broadway Magic  1987 Tempo/MSD Distribution Looks a lot like the NA version. 44 minutes.
Rock And Roll Express Rock and Roll Express Tempo Cover is horizontal, cardboard sleeve case 22 minutes.
2 Great Rock 'n' Roll Adventures A Presidential Dilemma, Journey Through Time. 1988 Tempo/MSD Distribution 44 minutes
The Fan The Fan, Roxy Rumbles. 1988 Tempo 44 minutes, weird redrawn cover art that I've never seen anywhere else.  Well, except for the Video Wars VHS box with Rock N' Curl Jem in a suspiciously familiar pose.
From London to Broadway Britrock, Broadway Magic 1988 Tempo 44 minutes, cardboard sleeve case
Music & Magic Music is magic, Rock & Roll Express, Britrock 1988 Tempo 67 minutes.  Seems to be a compilation of other Jem tapes.
Video Wars Video Wars, Homeland Heartland 1989 Tempo 44 minutes
Music Is Magic Music Is Magic
and trailer (? Not sure what that is)
1991 Tempo (Abbey Home Entertainment) Note: it's not called Music AND Magic which is a different video. 27 minutes.
photo neededThe Rock Fashion Book
Cover is mostly white, features full length Jem in the centre with small captures of each of the Holograms surrounding her. 
unknown unknown unknown 22 minutes
cardboard sleeve case.  As far as I know, this tape was only available as a free promotional item that came with some UK 1st edition Jem/Jerrica dolls (it was glued directly onto the flap!)
Hot Hits from the USA Maxies world: "Friend or UFO/ beach blanket battle"
Jem - "Hollywood Jem: for your consideration",
Hollywood Jem "...and the winner is'
Beverly Hills Teens: "The dog ate my homework"
unknown Tempo 94 minutes.(45 of which are Jem) Wow! Two really HTF Jem eps on here!  A "mixed" cartoon tape. 
photo neededJem: Truly Outrageous unknown unknown unknown Box is white, with Jem art of Jem singing with one arm over head, then there are small pictures of each of the holograms, and Jem in cartoon form around her. Never seen before or since, may not be UK, but is for sure Euro.

UK DVDs
All that I know of so far, surely there are more?  They are in Region 2, meaning they may not play in most North American DVD players.
Title Episodes Included date Distributor other
Girls World Unknown Which Jem Episode is on this, 
Also includes episodes of My Little Pony, Pongwiffy, Little Ghosts, Moon Dreamers
2004 Metrodome 108 Minutes. (22 of which are Jem)  Pink cover with 5 "bubbles", each bubble showing a small photo from each of the cartoons represented on the disc.
Girls World 2 The Rock Fashion Book
Also Includes Episodes of My Little Pony, Charmkins, and Moondreamers.
2005 Metrodome 108 Minutes. (22 of which are Jem)  Pink cover with rainbow coloured cross, each "arm" of the cross has a photo of the cartoons represented on the disc. 
Jem-The Movie The first five, as "Truly Outrageous!" the movie version. 2006 Metrodome/TV Loonland 90 minutes.  It is the Jem movie, which differs slightly from the episodes (some animation was cut into the episodes later, which isn't present here in the movie).  Personally I'm not nuts about the quality of this print but at least they managed to keep Pizzazz's hair the proper shade :)
Credits
Thanks KaraAria@aol.com for the information on the 1988 Annual.
Thanks to Brian (in Scotland :) for the UK Puzzle photos!
Thanks to Laura (Badgerprincess) for the Argos advertisement,
Thanks to Lynda for the UK box information.
For much more information on Jem in the UK, visit Taffeta's site, Britrock- The UK Home of the Misfits

Laura - Rock and Roll Express Video cover and back.
Dawn - Hot Hits from the USA