This is a list of unmade and unreleased television projects based on Marvel Comics. Some of these productions were, or still are, in development hell. Projects that have not provided significant production announcements within at least a year, would be considered in development limbo until further announcements are released. The following include live-action and animated productions created for television. Along with Marvel Comics properties, projects based on their imprints (Icon Comics, Malibu Comics, CrossGen, Star Comics, Razorline, and Epic Comics) are included.

In the 1950s, a television series based on the character Namor was planned starring Richard Egan, but it never finished production.

In the early 1970s, a different Sub-Mariner television pilot was in development but never finished filming due to the similarity of the short-lived Man from Atlantis series.

In 1975, Angela Bowie secured the TV rights to Daredevil and Black Widow for a duration of one year and planned a TV series based on the two characters. Bowie had photographer Terry O'Neill take a series of pictures of herself as Black Widow and actor Ben Carruthers as Daredevil (with wardrobe by Natasha Kornilkoff) to shop the project around to producers, but the project never came to fruition.

In 1983, ABC planned a live-action Daredevil pilot. Academy Award-winning writer Stirling Silliphant completed the draft of the program, but it was not aired.

In a 2002 interview with SFX magazine, Nicholas Hammond revealed that there were plans to do a reunion movie for The Amazing Spider-Man series in 1984. The proposal would have had the original cast team-up with the cast of The Incredible Hulk television series (a major hit for CBS), with Hammond appearing in the black Spider-Man costume. According to Hammond, a deal was arranged to have Columbia and Universal Studios co-produce the project. Bill Bixby was going to direct the TV-movie, in addition to reprising the role of David Banner. However, Universal eventually cancelled the project. Hammond said he was told that Lou Ferrigno was unavailable to reprise his role as the Hulk, because he was in Italy filming Hercules. However, in his 2003 autobiography My Incredible Life as the Hulk, Ferrigno stated that he was never contacted about the project, adding that he had recently finished filming Hercules II and that his availability was not an issue.

Philip DeGuere was given an ample budget for Dr. Strange, which he wrote, directed and produced. The film was shot on Universal sets in Los Angeles, going over-schedule by several days because of the special effects, which included a lot of the era's green screen. Friend and composer Paul Chiraha was encouraged to produce an electronic score. Chirara, interviewed in 2016, said that DeGuere had high hopes for the film, and was crushed when it "tanked".

In January 1985, Stan Lee recounted the largely positive experience of working on Dr. Strange, compared with the other live-action Marvel Comics adaptations under the publisher's development deal with CBS and Universal in the late 1970s, saying, "I probably had the most input into that one. I've become good friends with the writer/producer Phil DeGuere. I was pleased with Dr. Strange and The [Incredible] Hulk. I think that Dr. Strange would have done much better than it did in the ratings except that it aired opposite Roots. Those are the only experiences I've had with live action television. Dr. Strange and The Hulk were fine. Captain America was a bit [of a] disappointment and Spider-Man was a total nightmare." CBS did not pick up Dr. Strange as a series.