<Alireza Firouzja> (born June 18, 2003) from Iran apparently became the youngest *male* national chess champion of any country in history in January 2016 at age of <twelve years and 224 days>.

The 2015/16 Iranian Men's Final Chess Championship (1394 according to the Iranian (Persian) calendar) was organized in a closed, single round-robin tournament which took place in Tehran from January 20-28, 2016. Alireza Firouzja dominated that national championship in a field filled with young talents, but also veteran players such as top-seed Ehsan Ghaem Maghami.

<Niaz Murshed> (*1966) won the championship of Bangladesh at the age of 12 years and 309 days (according to Bill Wall who knows such things). This record stood for a long-time!

In 1978, Murshed finished first in the national championship with two others, but ultimately placed third on a tie-breaker. He went on to win the next four national championships in 1979, 1980, 1981 and 1982. He became the national chess champion again after 30 years in 2012. Murshed is Bangladesh's first ever GM, and the first South Asian Grandmaster, having been awarded the title in 1987.

<Henrique Mecking> (*1952) in 1967 at age of 13 yrs 5mths, Brazil: http://www.brasilbase.pro.br/bca196..., at that time a record, later surpassed / undercut by Niaz Murshed in 1979.

<Bobby Fischer> (*1943-2008) in 1957/8 at age of (near) 14, United States of America.

<Arturo Pomar> (*1931-2016) in 1946 at age of 15, Spain. Sometimes, Arturo Pomar is labelled as youngest national champion, winning the Championship of the Balearic Islands at the age of 11.

<Judit Polgar> (*1976) won the Men’s Hungarian Championship, played in Budapest in December 1991 (42th edition) at age of 15 and 5 months (unbeaten above joint 2nd-3rd Adorjan and Sax, ten players including her sister Zsuzsa Polgar and legendary Lajos Portisch), making her third and final GM norm.

In December 1991, Judit Polgar thus achieved the title of an International Grandmaster of Chess at the age of 15 years, 4 months and 28 days, at the time the youngest player ever to have done so, breaking the record previously held by former World Champion Bobby Fischer.

<Simen Agdestein> (*1967) became Norwegian national champion at age of 15+ in 1982. Agdestein and IM Bjorn Tiller shared first place in the Norwegian championship in the Summer. At the end of December 1982 they played a title match of four games. Agdestein won by 3-1 (+2=2).

<Magnus Carlsen> (*1990) became Norwegian national champion, too, at age of 15+ in 2006. The chess prodigy and his (former) teacher Simen Agdestein, tied for first at the Norwegian Championship in Summer 2006 in a 22-player 9-round Swiss tournament that was held in July 2006, in the city of Moss, just south of the capical of Oslo. To months later, Carlsen won the tie-break play-off to take the title.

<Wesley So> (*1993), Champion of the Philippines, winning the title in 2009 at age of 15yrs 6mths.

<Murray Chandler> (*1960), Co-Champion of New Zealand at age of 15 yrs and 8 mths. The NZL Championships in 1975/76 saw a triple tie for the title (without play-off), after Chandler lost in the final round to William Fairhurst (multiple Scottish Champion), thus allowing record title holder Ortvin Sarapu (born in Estonia, known in New Zealand as “Mr Chess”) and Lev Aptekar (ex-USSR), to catch up. First-timer in alphabetical order: Aptekar, Chandler, and Sarapu.

<Daniel Yanofsky> (*1925-2000) in 1941 at age of 16, Canada.

<Florin Gheorghiu> (*1944) in 1960 at age of 16, Romania.

<Wei Yi> (born 2 June 1999), in end of May 2015, Wei won his first Chinese Championship, breaking the previous national record of <Ding Liren> (born in October 1992, who had won the national title in May 2009 at age of 16 years and 7 months), becoming the youngest Chinese chess champion ever a few days before turning 16 years young.

<Akash G> (*1996, October) is India's youngest-ever national chess champion at 16 years and 14 days. In 2012, G. Akash, a student of computer science at Jawahar Higher Secondary School in Chennai won the National Premier Championship as untitled player.

<Murali Karthikeyan> (*1999, May) in 2015, <Viswanathan Anand> (*1969, December) in 1986, and <Dibyendu Barua> (*1966, October) in 1983 were all at age of 16 to 17.

Note: at the British Championship in Chester 1979, the 14-year-old Nigel Short tied for first place with John Nunn and Robert Bellin, earning his first IM norm, the title was won by Robert Bellin, subsequently Short cannot be counted then as National Champion even some sources do so.

Though some of the child prodigies («Wunderkinder») failed to fully fulfil their early promises (i.e. Niaz Murshed), or / and suffered severe illness (i.e. Pomar, Mecking), they remain strong players.

Other National Champion titles by the mentioned players have been omitted for reasons of consistency and clarity.

<Isabelle Kientzler>, later Isabelle Kientzler-Guerlain (born February 25, 1972) from France won her (first and only) national female title on July 4, 1984 at age of twelve years and 130 days.

<Hou Yifan> (*1994, February) won her first Chinese Women’s Chess Championship in Chongqing in June 2007 at age of 13 yrs and 4 mths, breaking WGM <Qin Kanying>'s (who was 14 when she won the title in 1988) record as the youngest Chineses champion. Hou scored 9/11 (+7 =4 -0, Elo TPR 2585).

<Humpy Koneru> (*1987, March) won the British Ladies’ Championship in August 2002 (BCF-ch 87th, a swiss system, won by Julian Hodgson as clear first, ahead of sole second Christopher Ward; Koneru as 21st best female player) at the age of 13 yrs 4 mths (breaking also a 61-year record held by the late Elaine Saunders Pritchard to become the youngest winner of the British Ladies title), and again in 2002, later also the female Indian Chess Championship.

In 2002, Koneru became the youngest woman ever to achieve the title of grandmaster (not solely a Woman Grandmaster) at the age of 15 years, 1 month, 27 days, beating Judit Polgár's previous mark by three months; this record was subsequently broken by Hou Yifan in 2008.

<Elaine Saunders Pritchard> (*1926, January, died in January 2012), child prodigy who won in Bournemouth in August 1939 the British women’s tournament at age of 13 yrs and 7 mths:

At the 1939 British Chess Federation Congress at Bournemouth, the proximity of war meant that the British Championship itself was not at stake. With the uncertainty of the time, and the absence of the players competing in the Buenos Aires Olympiad (Conel Hugh O'Donel Alexander, George Alan Thomas, Philip Stuart Milner-Barry, Harry Golombek and Baruch Harold Wood), the men’s championship was scrapped in favor of a more general Premier Tournament, won by Euwe.

<Nicola Tjaronda> (*1998) became Namibia’s youngest ever national chess champion since Independence at age of near 14 in 2012.

<Irina Krush> (*1983, December) won the U.S. Women’s Chess Championship in November 1998 at age of 15 minus one month to become the youngest U.S. Women's Champion ever.

<Jana Schneider> (*2002, April) won the German Chess Championship in April 2017 at 15 years, roughly at the same age as <Elisabeth Pähtz> (*1985) in 1999, and <Petra Feustel> (1958-2010), winning her first national Championship of East Germany in 1974.

<Alessia Santeramo> (*1998), girlfriend of Swiss GM Noel Studer, won the Italian Chess Championship in 2014 at age of 16.

<Listing may be incomplete>!!!

Especially, there are a lot of young female national champions; women competitions are much weaker on average. In a swiss system, the title is then awarded to the best placed women (no separate section).

<Viktor Korchnoi> (1931-2016) in 2011 at age of 80 years and four months, Switzerland, current world record!

<Hans-Uwe Kock> (1938, FIDE Master) in 2017 at age of near 79, his first national title, Liechtenstein (only five rounds, 15 players, there was no GM participating).

<Viktor Korchnoi> (1931-2016) in 2009 at age of 78 years and four months, Switzerland, setting then a new world record.

<51 years>, Viktor Korchnoi (from 1960 USSR-ch to 2011 SUI-ch).

Youth is ideally spent playing in the sun and socializing!>