Mighty Morphin Power Rangers (MMPR) is an American superhero television series that premiered on August 28, 1993, on the Fox Kids programming block. The show adapted stock footage from Japanese television series Kyōryū Sentai Zyuranger (1992–1993), which was the 16th installment of Toei's Super Sentai franchise. The second and third seasons of the show drew elements and stock footage from Gosei Sentai Dairanger and Ninja Sentai Kakuranger, respectively. The series was produced and distributed by Saban Entertainment.

It is the first entry of the Power Rangers franchise, which became a 1990s pop culture phenomenon, along with a large line of toys produced by Bandai, live tours, home media releases, and other merchandise, generating 1 billion dollars in revenue by 1995. It lasted three seasons and it was followed in 1996 by a mini-series titled Mighty Morphin Alien Rangers, while a global storyline would continue until its seventh season, titled Power Rangers Lost Galaxy. The subsequent seasons of the Power Rangers series would not be sequels or spin-offs in the traditional sense, having self-contained plots with no strong connection with the original series, while still taking place in the same universe. However, cast members and elements from Mighty Morphin Power Rangers would still be present on future iterations of the franchise, most notably, Jason David Frank reprising his role of Tommy Oliver in Power Rangers Dino Thunder.

The original series also spawned the feature film Mighty Morphin Power Rangers: The Movie, released by 20th Century Fox on June 30, 1995. Despite mixed reviews, it was a success at the box office and earned a cult following. A second film titled Turbo: A Power Rangers Movie was released in 1997.

In 2017, a feature film titled Power Rangers was released, serving as a reboot for the franchise. Due to both the film's financial failure and Hasbro's acquisition of the franchise in 2018, another reboot is in development.

A television special titled Mighty Morphin Power Rangers: Once & Always commemorated the 30th anniversary of the series and premiered on Netflix on April 19, 2023, with returning cast members David Yost, Walter Emanuel Jones, Steve Cardenas, Johnny Yong Bosch, Karan Ashley, Catherine Sutherland, Barbara Goodson and Richard Steven Horvitz reprising their roles, joined by Charlie Kersh, who portrayed Minh, the daughter of Trini Kwan.

The series takes place in the fictional town of Angel Grove, California. On an exploratory mission on the moon, two astronauts discover an extraterrestrial container (referred to as a dumpster) and breach the unit, inadvertently releasing the evil alien sorceress Rita Repulsa and her minions from 10,000 years of confinement. Upon her release, she and her army of evil space aliens set their sights on conquering the nearest planet—Earth. The wise sage Zordon, who was responsible for capturing Rita, later becomes aware of her release and orders his robotic assistant Alpha 5 to select five "teenagers with attitude" to defend the Earth from Rita's attacks. The five teens chosen are Jason Lee Scott, Kimberly Hart, Zack Taylor, Trini Kwan, and Billy Cranston. Zordon gives them the ability to transform into a superhuman fighting force known as the Power Rangers. This provides them with formidable abilities and an arsenal of weapons, as well as colossal assault vehicles called Zords which can combine into a giant humanoid robot known as the Megazord.

The series begins with the five teenagers combating Rita and her seemingly endless array of monsters, while also dealing with typical teenage problems and clashing with local bullies Bulk and Skull. However, consecutive failures lead Rita to adopt a new method for conquering Earth and destroying the Power Rangers—by attacking them with one of their own. Using her magic, Rita kidnaps and brainwashes a local teen whose fighting skills prove to equal that of Jason's in a martial-arts tournament held in Angel Grove. The new teen, Tommy Oliver, passes Rita's tests, becoming the Green Ranger. Entrusted with Rita's Sword of Darkness, the source for the continuance of the evil spell he has fallen victim to, Tommy comes dangerously close to defeating the Power Rangers. After sabotaging the Command Center and cutting off Zordon's connection to their dimension, Tommy helps Rita strike another blow to the Rangers when the Megazord is drained of its power in battle by a solar eclipse and then blasted into a molten lava crevice. However, Alpha eventually succeeds in reestablishing connection with Zordon, who then revives the Megazord. With it, the Rangers stop Tommy's rampage on Angel Grove with his Dragonzord, and Jason ultimately defeats Tommy in a one-on-one duel by destroying the Sword of Darkness. Now free from Rita's spell, Tommy chooses to use his Green Ranger powers to assist the Rangers in defeating the evil that gave it to him in the first place and the Dragonzord is reconfigured to enable it to help form more powerful Zord combinations alongside the other Dinozords.

As time goes on, Rita focuses on eliminating Tommy to regain the powers that she believes belong to her. Using a special wax that was touched by Tommy when he was brainwashed by her, Rita uses a magic Green Candle to slowly remove his powers, returning them to her. In the end, Tommy loses his powers, but he prevents Rita from reclaiming them by transferring them to Jason who, feeling guilt for failing to protect Tommy's powers, accepts them. However, Tommy later returns to the team when the other Rangers' Power Coins are handed over to Rita in exchange for their kidnapped parents. With Zordon's help, Tommy regains his powers and successfully retrieves the other Rangers' Power Coins. However, Tommy's regained powers are only temporary and must be frequently re-charged by Zordon, who warns him that the Green Ranger's powers will ultimately fail. Despite this, Tommy remains determined to continue assisting the other Rangers as long as possible.