The lyceum is a category of educational institution defined within the education system of many countries, mainly in Europe. The definition varies among countries; usually it is a type of secondary school.
Lyceum is a Latin rendering of the Ancient Greek Λύκειον (Lykeion), the name of a gymnasium in Classical Athens dedicated to Apollo Lyceus. This original lyceum is remembered as the location of the peripatetic school of Aristotle. Some countries derive the name for their modern schools from the Latin but use the Greek name for the ancient school: for example, Dutch has Lykeion (ancient) and Lyceum (modern), both rendered "lyceum" in English (note that in classical Latin the "C" in lyceum was always pronounced as a K, not a soft C, as in modern English).
In Pakistan in a small city called Dera Ghazi Khan there is a school named Lyceum High School. It was established in 1993 by its principal Javaid Iqbal. It only offers classes till eighth, but its studies match the level of its name as it uses all the foreign methods of teaching and stands with a slogan of "Lyceum: a school of creative thoughts."
The Goa Lyceum (Portuguese: Liceu de Goa) in Panaji, Goa – established in 1854, following the Portuguese model – was the first public secondary school in the state, then a Portuguese territory. Later, the Goa Lyceum received the official title of Liceu Nacional Afonso de Albuquerque (Afonso de Albuquerque National Lyceum).
The Philippines follows its version of the K-12 system, where the term junior high school might be used instead of lyceum. However, there are schools that appropriate the word "lyceum" in their brand. Lyceum of the Philippines University (LPU) is a university in Manila established by former wartime president José P. Laurel. Among its notable alumni are current president Rodrigo Duterte, popular author Rene Villanueva, and actor Cesar Montano. LPU has campuses in Makati, Batangas, Laguna, Cavite, and Davao. There are other schools that call themselves "Lyceum" but are unaffiliated with LPU.
The Turkish word for the latest part of pre-university education is lise which is derived from the French word "lycée" and corresponds to "high school" in English. It lasts 4 to 5 years with respect to the type of the high school. At the end of their "lise" education, students take the YGS / LYS test, i.e. university entrance examination, to get the right to enroll in a public university or a private university.
Lyceums also emerged in the former Soviet Union countries after they became independent. One typical example is Uzbekistan, where all high schools were replaced with lyceums ("litsey" is the Russian term, derived from French "lycée"), offering a three-year educational program with a certain major in a certain direction. Unlike Turkey, Uzbek lyceums do not hold University entrance examination, which gives students the right to enter a University, but they hold a kind of "mock examination" which is designed to test their eligibility for a certain University.
The Albanian National Lyceum was a high school in the city of Korçë, Albania, that emphasized the French culture and the European values. The school fully functioned with a French culture emphasis from 1917 to 1939. The school was continued post World War II as the Raqi Qirinxhi High School.
The Belarusian Humanities Lyceum is a private secondary school founded shortly after Belarus' independence from the USSR by intellectuals, such as Vincuk Viacorka and Uladzimir Kolas, with the stated aims of preserving and promoting native Belarusian culture, and raising a new Belarusian elite. It was shut down in 2003 by the Ministry of Education of Belarus allegedly for promoting enmity within Belarusian society and using the classroom as a political soapbox, indoctrinating students with biased views on history, ideology, politics, morality and values. The lyceum eventually switched to homeschooling with a limited number of underground home schoolers.
The term lyceum refers to a type of secondary education consisting of anywhere from 4 years ended by graduation. It is a type between grammar school and a technical high school. For example, the famous scientist Gerty Cori went to a "lyceum" school.
The concept and name lyceum (in Swedish, lyseo in Finnish) entered Finland through Sweden. Traditionally, lycea were schools to prepare students to enter universities, as opposed to the typical, more general education. Some old schools continue to use the name lyceum, though their operations today vary. For example, Helsinki Normal Lyceum educates students in grades 7–12, while Oulu Lyceum enrolls students only in grades 10–12. The more commonly used term for upper secondary school in Finland is lukio in Finnish, gymnasium in Swedish.
Senior or Upper Secondary Education School (lyceum, high school). For students aged ~ 14/15 to 18. 
The Evening Lyceum (Εσπερινό) is at both for adult students and underage working students lasts
3 years (former 4 years) since 2020–2021 academic year by Law 4547/2018. Lyceum awarded
Απολυτήριο, Apolytirion, (upper secondary leaving certificate or high school diploma).
Upper Secondary School (Lyceum):
Other type of Upper Secondary School:
Other defunct type of Upper Secondary School was operated by Ministry of Education:
Defunct Upper Secondary School (Lyceum):
Before World War I, secondary education institutes with a primary goal of preparing for higher studies were often referred to by the word líceum.
In contemporary Hungarian, the most ubiquitous word for these institutions is gimnázium, but líceum lives on as an archaizing word referring to schools of high prestige and revered traditions, most notably Calvinist boarding schools.
In Italy the term liceo refers to a number of upper secondary school, which last 5 years (from 14 to 19 years) and are specialized in teaching math, ancient Greek, and Latin. It gives preparation for university. It’s divided into four different branches, each one specialized in certain subjects:
The lyceum is considered by most the hardest and most prestigious kind of secondary school in Italy.
Some gymnasiums are called licėjus, e. g. Vilnius Lyceum.
Junior lyceums refer to secondary education state owned schools.
Until recently, in the Republic of Moldova the lyceum - called liceu - was an educational institution where students studied from the first to the twelfth grade and would obtain the Baccalaureate degree upon completion. In most cases, the lyceums were specialized in a particular domain (fine art, theatre, language) that was relevant to the personality whose name the institution bore. In other respects, it was little different from any regular school, with the exception of slightly higher education standards and supposedly being more prestigious. After 2010, regular schools were all formally reformed into lyceums, although their quality remained of the same level as before and most did not get any particular specialization, thereby being dubbed 'Theory Lyceums' ('Liceu Teoretic'). One reason for the 2010 reform was to reduce the influence of the Soviet/ Russian educational system and/ or mentality in Moldova.
In the Netherlands, a lyceum is a selective secondary school for children aged 12–18 that offers "voorbereidend wetenschappelijk onderwijs" (vwo) and "hoger algemeen voortgezet onderwijs" (havo), the top and middle levels of secondary education available in that country. Successful completion allows vwo students admission to university and havo students to hogeschool, comparable to vocational university. The term lyceum is also sometimes used for other vocational schools such as the Grafisch Lyceum, or Muzieklyceum Amsterdam, which grew into the Conservatorium van Amsterdam.
The liceum is the Polish secondary-education school. Polish liceums are attended by children aged 16 to 19–21 (see list below). Before graduating, pupils are subject to a final examination, the matura.
Polish liceums are of several types:
From 1836 until 1978, in the Portuguese educational system, the lyceum (Portuguese: liceu), or national lyceum (Portuguese: liceu nacional), was a high school that prepared students to enter universities or more general education. On the other hand, the technical school (Portuguese: escola técnica) was a technical-oriented school.
After several education reforms, all these schools merged into a single system of "3rd cycle basic" and secondary schools (Portuguese: escolas básicas do 3.º ciclo e secundárias), offering grades 7 to 12.
The Romanian word for lyceum is liceu. It represents a post-secondary form of education. In order for a student to graduate the lyceum and obtain a baccalaureate diploma, they must pass the bac. The lyceum consists of four school years (15–19). Although the lyceum is a pre-university educational institution, it can be enough for the graduates to find a job, mainly as office work.
In Imperial Russia, a Lyceum was one of the following higher educational facilities: Demidov Lyceum of Law in Yaroslavl (1803), Alexander Lyceum in Tsarskoye Selo (1810), Richelieu Lyceum in Odessa (1817), and Imperial Katkov Lyceum in Moscow (1867).
The Tsarskoye Selo Lyceum was opened on October 19, 1811 in the neoclassical building designed by Vasily Stasov and situated next to the Catherine Palace. The first graduates were all brilliant and included Aleksandr Pushkin and Alexander Gorchakov. The opening date was celebrated each year with carousals and revels, and Pushkin composed new verses for each of those occasions. In January 1844 the Lyceum was moved to Saint Petersburg.
During 33 years of the Tsarskoye Selo Lyceum's existence, there were 286 graduates. The most famous of these were Anton Delwig, Wilhelm Küchelbecher, Nicholas de Giers, Dmitry Tolstoy, Yakov Karlovich Grot, Nikolay Yakovlevich Danilevsky, Alexei Lobanov-Rostovsky and Mikhail Saltykov-Shchedrin.
The Lyceum of the Principality of Serbia was the first higher education school in Serbia in which education was taught in Serbian. It was founded in 1838 on the initiative of Prince Miloš Obrenović II in 1838 in Kragujevac, then the capital of Serbia. When Belgrade became the Serbian capital in 1841, the Serbian Lyceum opened there. In 1863 it became known as the Grandes écoles until 1905 when it officially changed its name to the University of Belgrade.
It is not uncommon in Chile to use the word liceo when referring to a high school. Another term is "enseñanza media" (secondary education); however, liceo is the most common term due to Chile's extensive European influence.