Mighty Morphin Power Rangers (MMPR) was an American live-action television series, created for the American market based on the sixteenth installment of the Japanese Super Sentai franchise, Kyouryuu Sentai Zyuranger. The show and its related merchandise both saw unbridled overnight success, catapulting into pop culture in mere months. Under the original name Mighty Morphin Power Rangers, the series ran from 1993 to 1996 and spawned a feature (non-canon) film, Mighty Morphin Power Rangers: The Movie.

The second and third seasons drew on footage and elements from the Japanese series Gosei Sentai Dairanger and Ninja Sentai Kakuranger respectively, though the Zyuranger costumes were still used extensively; the main 5 Dairanger suits were never used at all, only the KibaRanger (White Power Ranger) suit was used.The series takes place in the fictional town of Angel Grove, California. Two unwitting astronauts on a lunar exploration discover a dumpster and release Rita Repulsa from 10,000 years of confinement. Upon her release, she and her army of evil Space Aliens set their sights on conquering the Earth. When the wise sage Zordon becomes aware of the release of the evil witch he was responsible for capturing so long ago, he orders his robotic assistant, Alpha 5, to find five "teenagers with attitude," to defend the Earth from Rita's attacks. The five socially diverse teens, Jason, Trini, Billy, Kimberly, and Zack, are chosen.

The series begins with the five teenagers combatting Rita Repulsa and her seemingly endless array of monsters, 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. In possession of a special Green Ranger power, Rita kidnaps and brainwashes a local teen whose fighting skills prove to equal that of Jason Lee Scott's in a Martial Arts contest held in Angel Grove. The new teen, (Tommy), passes Rita's tests, earning the Green Ranger Power during the story arc "Green with Evil." Eventually, the Green Ranger is overcome and the Sword of Darkness, the source of the evil spell he has fallen victim to, is destroyed by Jason. As a result, Tommy will use the powers he's left with to defeat the evil that gave them to him in the first place. His Zord, the Dragonzord, retains the power to join with the other Ranger's Zords to form more powerful Zord combinations.

Discontent with regularly being defeated with the aide of the Green Ranger powers she believes are hers, as time goes on, Rita focuses her plans on eliminating Tommy and regaining the Powers. Utilizing a special wax adapted to Tommy's touch, Rita uses a green candle (in a story arc under the same title) to sever Tommy's link to the Morphing Grid and slowly remove his powers, returning them to her. Because Tommy's presence accelerates the candle's melting process, an unmorphed Jason instead must enter the Dark Dimension and face down Goldar to retrieve the candle. Unfortunately, Rita unleashes concurrent monster attacks in Angel Grove that keep Jason and his friends from retrieving the candle. In the end, Tommy is robbed of his Powers, however, he is able to prevent Rita from retaining the Powers by transferring them to another Ranger who can operate them based off their own link to the Morphin Grid. Tommy chooses Jason who, though riddled with guilt for failing to protect Tommy's Powers, accepts them. Though Tommy loses his Ranger powers, he gains a girlfriend: Kimberly Hart, the Pink Ranger, whose affections for Tommy transcend his status as a Ranger.

The five Rangers continue to protect Earth from the ongoing threat of Rita Repulsa, with Jason wielding the Green Ranger powers in conjunction with his own Red Ranger Powers. In a story arc seeing the kidnap of the parents of all the students at Angel Grove High School, including that of the five Ranger teens, the Ranger's are forced to give up their five Power Coins in trade for their parents safety. In an act of subterfuge, Goldar accepts the Coins and keeps the captive parents. To make matters worse, Rita brainwashes Billy into stealing the Dragon Dagger and giving it to Goldar who unleashes the mighty Zord upon a town that no longer has the protection of the Power Rangers. With no powers of their own to use, Jason reveals that he is still in possession of the Dragonzord Power Coin. Tommy returns, agreeing to take part in a dangerous process in which Zordon will transfer energy from himself and into the Power Coin, allowing it to temporarily enable Tommy to Morph into the Green Ranger once more. He steals back the coins and Dagger at the cost of his own life, having been electrocuted by a force-field protecting both sets of items. The Rangers regain their Powers and fight for the safety of their parents, to no avail as Rita's latest monster brainwashes the rest of the team and turns them against Kimberly. In a turn of events, Tommy is resurrected; it is revealed that he'd been energized by the power of the force-field that electrocuted him. He once again uses his Powers to save the day, but they are only temporary and can be re-generated only for a short time by Zordon who will continue to use his own energy to supplement Tommy's failing ones, making no attempts to hide the fact that the Green Ranger's Powers will ultimately fail. With every battle that occurs from here on, Tommy is left to decide whether or not he will get involved and waste away he last of his Powers.

Following multiple defeats, Rita's fortress is invaded by her superior, Lord Zedd. Disgusted with her failure, he takes over, discarding Rita back into space within another Dumpster, then launches his own campaign against the Power Rangers, this time focusing on turning living things into monsters in order to waver the Ranger's ability to destroy them. As Zedd focuses his attacks on the Green Ranger powers that continue to waste away with every battle he engages in, the other Ranger's see an upgrade to their Powers as they adapt to take on the Power of Thunder, a power that also transforms their Dinozords into mythical beasts known as Thunderzords, also able to form brand new, more powerful Zord combinations.

Things are complicated by the creation of the White Power Ranger (inevitably given to Tommy), the Power Transfer (from Jason, Zack and Trini to Rocky, Adam and Aisha respectively), and the return of Rita, who ingratiates herself by slipping Zedd a love potion. Unhappy with the return of the evil witch who had mistreated him and forced him into servitude, Goldar will make several attempts to turn Lord Zedd against Rita to get rid of her once and for all. However, after Goldar discovers that Rita gave Zedd a love potion, he is dismayed to find that even after he bullies Finster into administering an antidote, Zedd truly loves her anyway.

Rito Revolto, Rita's skeletal brother, later comes to Earth and manages to destroy the Rangers' Thunderzords and, consequently, the Thunder Powers along with them. Undaunted, they seek the aid of Ninjor, alleged creator of the Power Coins, who gives them new Ninja powers.

Later, a blonde Australian girl named Kat moves to Angel Grove. She befriends Kimberly, and displays an intense affection for Tommy. Later, it is found that Rita captured Kat and put her under a powerful spell. As a result, she steals Kim's Pink Crane Ninja Coin, vastly weakening the Pink Ranger whose life force, like that of the other Ninja Ranger's, is connected to their Ninja Coins. Kat eventually overcame the spell, and gave the coin back to Kimberly. Having already been disconnected from the Power Coin when the weakening link threatened her life, and told by Zordon that her duties have been fulfilled, Kim now has a chance to pursue her personal athletic dreams. Still unwilling to give up her role as defender of the Earth, in the end, Kimberly is convinced by her friends to retire as a Ranger. She leaves to train for the Pan Globals, deciding to entrust the Crane Coin to Kat for her humanitarian efforts, making her the new Pink Ninja Ranger. Though her initial fear and hesitation keeps her from contributing fully to the fight against evil, Kat eventually becomes both more comfortable and capable of fulfilling the duties entrusted to her by Kimberly.

After several more battles, Zedd and Rita are joined by Rita's father, Master Vile. Following his failed attempts to defeat the Rangers, he reverses time, destroying the Ninja powers and eliminating the threat of Ninjor. These events culminate in the Mighty Morphin Alien Rangers mini-series, and end with a cliffhanger seeing the destruction of the Command Center, with Zordon and Alpha 5 trapped inside. These events lead into the next season and incarnation of the Power Rangers series, titled Power Rangers