This is an event where a network will run multiple episodes of the same show back-to-back for an extended period of time. It can also take the form of running all of the movies in a given franchise back-to-back.
Often done as a promotional event. A popular series will marathon all previous episodes prior to the start of the newest season. The release of a new film in a franchise will be preceded by a marathon showing of all previous films in that franchise. In addition to providing publicity, this gives the audience a chance to get up to speed with events in the show before they jump into the new season. Sometimes, it's also done with really, really popular shows to crank up the overall ratings.
- Fox Kids used to love marathon running for Power Rangers and Digimon. In fact, that was how the American premieres of Digimon Adventure 02 and Digimon Tamers were set up.
- Cartoon Network has frequently marathoned Naruto. One of the most notable examples was the Naruto Hundo, done to celebrate the milestone of Naruto reaching 100 aired episodes on Toonami.
- For most of 2007-2008, they ran two-episode blocks back-to-back (sometimes advertised as "mini-marathons") in order to burn through Filler.
- Note that this is only in the present. Cartoon Network and ESPECIALLY Nickelodeon had frequent marathons, almost every night and every Saturday of shows or shows with a vague similar theme before their Network Decay.
- Cartoon Network helped turn The Iron Giant, a box-office flop in theaters, into a cult favorite with its 24-hour Thanksgiving Day marathons in the early 2000s.
- The channel used to have 48 hours of nothing but Bugs Bunny cartoons in June - "June Bugs".
- Let's not forget Z Day, a 2-hour marathon of Dragon Ball Z.
- "DBZX20" - Nothing but Dragon Ball Z on Toonami for an entire week.
- Also the annual Cartoon Cartoon Weekend, a full weekend of original series (with a few new surprises).
- In the mid-90s, Cartoon Network Europe did (at least) a full weekend The Flintstones marathon and upped it to eleven by doing a FULL WEEK MARATHON of Scooby-Doo.
- Cartoon Network Latin America is fondly of this too, especially before their Network Decay in late 2000s. If you want to talk about New Year's Eve, for example, for three years in a row (during earlier 2000s they went a little step further: 24 hours of Pokémon and one of those years it was 48 hours! Special mention goes to the 2004 New Year's Eve when they not only premiered Foster's Home for Imaginary Friends but also changed their Powerhouse era look into their then-new City look.
- [adult swim] usually does marathons around holidays, especially in December.
- There have been marathons of The Venture Brothers, Bleach, Robot Chicken, Metalocalypse, Squidbillies, The Boondocks, Futurama (every episode one after the other, RIGHT before its license expired,) Family Guy, FLCL, and even all four InuYasha movies. An April Fools marathon of Perfect Hair Forever played all seven episodes in backwards order with bad subtitles.
- Let's not forget the other April Fools day marathon, in which they showed the same episode of Harvey Birdman 24 times in a row.
- According to the rumors, the Futurama one was a Take That at Comedy Central, which had just gotten the license - they were attempting to make people sick of it.
- They aired a Moral Orel marathon on New Year's Eve. Most depressing way to start 2009 ever.
- Over the Christmas 2007 holiday Britain's Anime Central broadcast marathons of Cowboy Bebop (26 episodes), Fullmetal Alchemist (51 episodes) and Bleach (the first 52 episodes). Unfortunately this meant that several other shows were cut short before Christmas and not resumed afterward.
- Prior to the release of Casino Royale, the films of the James Bond franchise were marathoned. In fact, whichever cable channel currently has the rerun rights to the films does this on a fairly regular basis. They were marathoned on TBS and TNT in The Nineties to the point that in American Beauty, Lester complains about having to go to the basketball game to watch his daughter in the cheerleading squad because he's missing one of these.
- Turner Network Television (TNT) will often run the same film back-to-back with itself for people that happen upon it part way through.
- In 1997, they decided to do a 24-hour marathon of A Christmas Story on Christmas Eve as a ratings stunt. It was so phenomenally successful that either TNT or sister channel TBS has done it every single year since then.
- As a Take That to A Christmas Story, FX now does a 24-hour marathon of Home Alone on Christmas Eve.
- TNT also used to run daily six-hour marathons of Law & Order.
- Nickelodeon marathoned Avatar The Last Airbender prior to the premiere of the third season.
- As a result of scheduling, Spongebob Squarepants will often be played for what would qualify as marathons. Frequently, they show marathons of it for the debut of new episodes.
- Nickelodeon had a short marathon block in 1999, with different episodes of Nick shows airing, but with a similar theme. It was known as 101% Whizbang! With Henry & June.
- It was replaced with U Pick in very late 1999, with Henry and June hosting until the block's demise in 2000. You voted for the show you wanted online, and they'd show a little marathon of it or something. (U Pick returned in `02, but with live action hosts, and every day unlike the Henry and June one, which was Fridays)
- Nick At Nite and TV Land used to do these a lot, although lately they've fallen by the wayside due to the dreaded Network Decay.
- MTV, before Network Decay fully took hold, used to marathon Beavis And Butthead occasionally, dubbing them "Moron-a-Thons".
- When The Monkees began airing in reruns on pre-Network Decay MTV in February 1986 (The group's 20th anniversary), it was launched by a weekend marathon featuring every Monkees episode. The marathon proved to be so successful, that the Monkees regained an entirely new generation of fans. Monkeemania was offically reborn. This was followed by several concert tours, a new album ("Pool It!"), a horrible Spin-Off (The New Monkees) and a top 20 hit single ("That Was Then, This Is Now").
- The Discovery Channel once had an "Explosion Sunday" event. It consisted, naturally, of a marathon of Mythbusters.
- Mystery Science Theater 3000 was famous for its "Turkey Day" marathons during the Comedy Central era, in celebration of the show's anniversary (which was in fact on Thanksgiving.) Made even cooler with the addition of specially-produced host segments to tie the shows together.
- The Sci Fi Channel (now Syfy) typically airs a Twilight Zone marathon on New Year's Day and other holidays.
- In previous years, they've run weekend-long marathons of various Godzilla films, and at least one weekend of showing every Planet of the Apes film.
- They also ran a 13-hour marathon of the 1966-67 series The Green Hornet on Jan 11, 2011 to mark the opening of the Green Hornet movie adaption opening later in the week.
- The first few years of the channel, the time between Christmas and the New Year would be "Sci-Fi Movie Supernova." Possibly the longest televised marathon, it was a week of non-stop movie broadcasts.
- A Merlin marathon always airs before the start of a new season and as a catch up opportunity the day of the season finale.
- USA Network airs periodic weekend marathons of Law & Order: Special Victims Unit, combined with weekday airings that remind one of the event. Then there's its "Back-to-back-to-back NCIS" feature every day. It will also frequently run much longer marathons of the same show.
- Oh admit it, USA will run marathons of anything... and we love when they do.
- Turner Classic Movies often airs marathons dedicated to a particular actor, director, genre, or theme. The channel's annual "31 Days of Oscar" feature each February might be regarded as a month-long supermarathon, with every movie shown being at least nominated for an Oscar of some kind. (It's 31 days long because the ceremony, and thus the marathon, used to take place in March; when it was moved back, they kept the number of days and let it bleed into the next month.)
- Oh, does the Science Channel ever love to run How It's Made for hours on end. They even ran every episode ever aired at the start of February 2011, which took five days to get through.
- A&E likes to marathon CSI: Miami - a lot.
- AMC does four episodes in a row per day on the show also.
- The other shows aren't immune. Spike runs 4 CSI: Crime Scene Investigation eps a day and TNT runs 3 or 4 CSI NY eps a day.
- The TV Guide Channel loved to run Michael Jackson specials a lot after his death, which turned out to be a convenient excuse to throw the network's old management out and launch all-new programming from new owner Lionsgate in the fall.
- For many years New York station WOR-TV had a tradition of airing King Kong, Son of Kong, and Mighty Joe Young back to back on Thanksgiving Day, followed by several Godzilla films on the day after Thanksgiving.
- Fellow New York station WPIX used to have their own holiday tradition as well, running 12 to upwards of 25 hours of The Twilight Zone on Independence Day.
- Several channels have shown New Years Eve marathons of The Three Stooges, most notably AMC, although the occasional local channel may do it too depending on your area.
- A few days before Christmas 2011, The Hub ran two mini-marathons of My Little Pony: Friendship Is Magic in a row, one themed about Discord and consisting of The Return Of Harmony, Part 1 and The Return Of Harmony, Part 2, and another themed about Pinkie Pie, and consisting of Feeling Pinkie Keen and Party Of One, to celebrate those characters having won the Naughty Or Nice contest.
- ON Dec 31, 2011/Jan 1, 2012 Antenna TV ran "Night of 2012 Laughs", a 20 hour marathon of episodes of The Burns And Allen Show and The Jack Benny Program.
- TBS airs Family Guy for three hours solid every Monday night.
- In another pre-Network Decay example, Bravo used to have occasional "Cirque du Soleil Weekends" featuring the shows that had been filmed for TV/video.
- In mid-2012, at least one PBS station (North Carolina's UNC-TV) ran the entire second season of Downton Abbey in one day.
- Every groundhog day, one of the spanish Canal+ film channels (usually Canal+ Comedia) runs a full-day marathon of (as you may have guessed) Groundhog Day.
- German-Austrian-Swiss channel ''3Sat'' runs a 24-hour pop-music concert marathon every December 31st and every May 1st.
- BBC Parliament occasionally devotes an entire day to rerunning an entire election coverage. The last one being the General election of 1974.
- In its earlier days,Game Show Network loved this trope,especially for holidays.
- ABC, Disney Channel, and Toon Disney would often run marathons of Recess; heck, the show had a day-long marathon the day Toon Disney started airing it!
- Around 2003-2004, Disney Channel and Toon Disney usually used any holiday where kids would be off from school as an excuse to play Recess marathons.
- To prepare for the release of the third Lord of the Rings film in 2003, Starz ran a 24-hour marathon of the first Lord of the Rings film and the making of featurettes for all three films, capping it off with the television premiere of the second film.
- ION Television airs eight hours of reruns of Cold Case on Fridays.