Power Rangers is a long-running American entertainment and merchandising franchise built around a live action children's television series featuring teams of costumed heroes. Produced first by Saban Entertainment, later by BVS Entertainment, and currently by SCG Power Rangers LLC, the television series takes much of its footage from the Japanese tokusatsu Super Sentai, produced by Toei Company. Its first entry, Mighty Morphin Power Rangers, debuted on August 28, 1993, and helped launch the Fox Kids programming block of the 1990s, during which it catapulted into popular culture along with a line of action figures and other toys by Bandai. The first nine seasons would air entirely on Fox Kids. However, in 2001, The Walt Disney Company bought the franchise while production was beginning on the tenth season, Power Rangers Wild Force. The first 26 episodes would air on Fox Kids, while the remaining 14 episodes would air on ABC Kids and ABC Family.
After Wild Force, Disney had planned to cancel the show, and air reruns. However, it was suggested that if production moved to New Zealand, the show could keep going and be cheaper to produce. Season 11, Power Rangers Ninja Storm, was the first filmed in New Zealand, where it has been filmed ever since. For Season 12, Jason David Frank, who played Tommy Oliver for the first five seasons of the show, returned as the team's mentor and Black Ranger. This was done as a favor to Executive Producer Doug Sloan and as a way to show that the New Zealand-produced seasons were in canon with the previous ten.
Despite initial criticism for its action violence targeted to child audiences, the franchise has continued, and as of 2020, the show consists of 27 television seasons and three theatrical films. Creator Haim Saban regained ownership of the franchise in 2010 after seven years under The Walt Disney Company. In May 2014, Saban and Lionsgate announced plans to do a film reboot of Mighty Morphin Power Rangers.  A release date has been set for March 24, 2017. On February 2, 2016, it was announced that actress Elizabeth Banks (The Hunger Games) would play Rita Repulsa. On June 21, 2016, Bryan Cranston was announced to be playing Zordon. On September 22, 2016, Saturday Night Live alum Bill Hader was announced to be playing Alpha 5. 
The first six seasons of Power Rangers are collectively referred to as the Zordon Era. This is because all six seasons were connected with each other in that they were continuations of previous ones. After the first three seasons of Mighty Morphin Power Rangers, producers decided it was time for a major overhaul of the show. As a result, the show was renamed Power Rangers Zeo for it's fourth season. The following season, Power Rangers Turbo, is widely regarded as one of the worst seasons of all time, mainly due to the motif being automobiles and the inclusion of a child ranger, Justin Stewart. After the dismal performance of Turbo, Saban was given one last season to wrap up the storyline, resulting in Power Rangers in Space. The sixth season of Power Rangers would prove to be very popular, enough to renew the show. However, the storyline first started in Season One ended with the 2-parter, Countdown to Destruction.
After the successful performance of Power Rangers in Space, the show continued with Power Rangers Lost Galaxy. Lost Galaxy would become one of the most expensive seasons ever produced. It also had some ties to the Zordon Era, acting as an epilogue of sorts. It wouldn't be until Power Rangers Lightspeed Rescue that the show would have no ties to previous seasons, save for the annual team-up with the previous one. Power Rangers Time Force is regarded as one of the best seasons, due to better acting and writing. However, episodes were edited after the September 11, 2001 terrorist attacks. Power Rangers Wild Force would be the tenth anniversary of the series, as well as the last one produced in the United States. In 2001, just as Wild Force was beginning production, Disney would purchase Power Rangers from Saban.
After the purchase by Disney, the initial plan was to air Power Rangers as reruns following the completion of Power Rangers Wild Force. However, it was suggested that if production moved to New Zealand, the show could continue with a smaller budget. Power Rangers Ninja Storm would be the first New Zealand-produced season, airing in 2003. Producers Doug Sloan and Ann Austen returned to the series, being absent for several years. However, Ninja Storm would be the first season since Lost Galaxy to not have a team-up episode. This was mainly due to the Wild Force cast being union actors, while Ninja Storm was a non-union project. This, coupled with several lines said throughout the series made fans think Ninja Storm was in a different continuity than the previous ten seasons. For the next season, Power Rangers Dino Thunder, Jason David Frank, who played Tommy Oliver in the first five seasons of the show, returned as the team's mentor and later, Black Ranger. This season also featured a team-up with the Ninja Storm rangers, proving it was in the same continuity. After Doug Sloan left the show, Bruce Kalish was brought on as Executive Producer for Power Rangers S.P.D.. S.P.D. would prove to be a popular season among fans, with its successor, Power Rangers Mystic Force, receiving a slightly less reaction. Power Rangers Operation Overdrive was the fifteenth anniversary of the series. Unfortunately, many fans see it as the absolute worst season of Power Rangers. Power Rangers Jungle Fury would garner a better reaction the next year, although Jungle Fury went into production during the Writer's Strike. After Jungle Fury, Kalish left, and Eddie Guzelian was brought on as EP for Power Rangers RPM. RPM would be set in an alternate, dystopian future, similar to Mad Max. It was also the last season produced by Disney. In 2010, Disney aired a poorly-received "re-versioning" of Mighty Morphin Power Rangers. In response, Saban, re-acquired the franchise in May of that year.
With Power Rangers back in the hands of Saban, a new season based on the 33rd Super Sentai series, Samurai Sentai Shinkenger, was set to premiere on Nickelodeon in February 2011, as Power Rangers Samurai. Promotion for the show was very similar to how it had been during the MMPR days. However, only 20 episodes would air in 2011. The remaining ones would air in 2012, under the name Power Rangers Super Samurai. For the 20th anniversary of the series, a bit of a problem arose. Usually, the anniversary seasons coincided with their Super Sentai counterparts. However, there was still one more Sentai season to go before getting to what was the 35th anniversary of Super Sentai, and adapting it into the 20th anniversary of Power Rangers. Power Rangers Megaforce would be adapted from Tensou Sentai Goseiger, the 34th series, while Power Rangers Super Megaforce was adapted from Kaizoku Sentai Gokaiger, the 35th anniversary of Super Sentai. Both seasons received a lukewarm reaction from fans, with many saying it was rushed. In 2015, fans were expecting an adaptation of Tokumei Sentai Go-Busters, the 36th Super Sentai. However, Go-Busters would be the first series since the start of Power Rangers to be skipped over in favor of Zyuden Sentai Kyoryuger, which was adapted into Power Rangers Dino Charge. Similar to Samurai, the latter half of Dino Charge would air in 2016 as Power Rangers Dino Supercharge. Rumors abound during 2015 suggested that Saban did not like Ressha Sentai ToQger, which was the Sentai series that followed Kyoryuger. It was speculated that the 2015 Super Sentai series, Shuriken Sentai Ninninger, may be adapted instead. This was confirmed on January 9, 2016, it as was reported that SCG Power Rangers LLC had filed a trademark for "Ninja Steel."  This effectively made ToQger the second Sentai to be skipped since the advent of Power Rangers.
In February 2018, it was announced that Hasbro would be acquiring the Master Toy License from Bandai. Shortly after, Power Rangers Beast Morphers was announced as the 26th season, based on Tokumei Sentai Go-Busters. Beast Morphers would also be the first season since seasons had been split into to groups of 20 episodes to not have a "Super" in the title of the latter half of the run. In addition to the standard Beast Morphers toy line, Hasbro announced the "Lightning Collection," which is the equivalent of lines as the Star Wars Black Series and Marvel Legends, both of which are also made by Hasbro. In 2020, Hasbro announced that season 28 would be called Power Rangers Dino Fury, based on the 2019 Sentai, Kishiryu Sentai Ryusoulger. Dino Fury will be the fifth season in the history of the series to have a dinosaur motif. On September 8, 2020, the potential cast of Dino Fury was leaked. The cast includes a female green ranger, which in the Sentai was male. This will be the first season to have a gender swapped ranger since 2002's Power Rangers Wild Force. 
- Kyoryu Sentai Zyuranger (1992) - Mighty Morphin Power Rangers: Season One (1993)
- Gosei Sentai Dairanger (1993) - Mighty Morphin Power Rangers: Season Two (1994)
- Ninja Sentai Kakuranger (1994) - Mighty Morphin Power Rangers: Season Three (1995)/Mighty Morphin Alien Rangers (1996)
- Choriki Sentai Ohranger (1995) - Power Rangers Zeo (1996)
- Gekisou Sentai Carranger (1996) - Power Rangers Turbo (1997)
- Denji Sentai Megaranger (1997) - Power Rangers In Space (1998)
- Seijuu Sentai Gingaman (1998) - Power Rangers Lost Galaxy (1999)
- Kyuukyuu Sentai GoGoV (1999) - Power Rangers Lightspeed Rescue (2000)
- Mirai Sentai Timeranger (2000) - Power Rangers Time Force (2001)
- Hyakujuu Sentai Gaoranger (2001) - Power Rangers Wild Force (2002)
- Nipuu Sentai Hurricanger (2002) - Power Rangers Ninja Storm (2003)
- Bakuryuu Sentai Abaranger (2003) - Power Rangers Dino Thunder (2004)
- Tokusou Sentai Dekaranger (2004) - Power Rangers S.P.D. (2005)
- Mahou Sentai Magiranger (2005) - Power Rangers Mystic Force (2006)
- GoGo Sentai Boukenger (2006) - Power Rangers Operation Overdrive (2007)
- Juken Sentai Gekiranger (2007) - Power Rangers Jungle Fury (2008)
- Engine Sentai Go-Onger (2008) - Power Rangers RPM (2009)
- Samurai Sentai Shinkenger (2009) - Power Rangers Samurai (2011)/Power Rangers Super Samurai (2012)
- Tensou Sentai Goseiger (2010) - Power Rangers Megaforce (2013)
- Kaizoku Sentai Gokaiger (2011) - Power Rangers Super Megaforce (2014)
- Zyuden Sentai Kyoryuger (2013) - Power Rangers Dino Charge (2015)/Power Rangers Dino Super Charge (2016)
- Shuriken Sentai Ninninger (2015) - Power Rangers Ninja Steel (2017)/Power Rangers Super Ninja Steel (2018)
- Tokumei Sentai Go-Busters (2012) - Power Rangers Beast Morphers (2019-2020)
- Kishiryu Sentai Ryusoulger (2019) - Power Rangers Dino Fury (2021)
Unadapted Sentai Series
Although most series since Kyoryu Sentai Zyuranger were adapted into seasons of Power Rangers, some were not, or have yet to be.
- Ressha Sentai ToQger (2014) - Some of the villain costumes were used for Power Rangers Ninja Steel.
- Doubutsu Sentai Zyuohger (2016)
- Uchu Sentai Kyuranger (2017)
- Kaitou Sentai Lupinranger VS Keisatsu Sentai Patranger (2018)
- Mashin Sentai Kiramager (2020)
- Mighty Morphin Power Rangers: The Movie (1995)
- Turbo: A Power Rangers Movie (1997)
- Power Rangers (2017)