Language assessment or language testing is a field of study under the umbrella of applied linguistics. Its main focus is the assessment of first, second or other language in the school, college, or university context; assessment of language use in the workplace; and assessment of language in the immigration, citizenship, and asylum contexts. The assessment may include listening, speaking, reading, writing, an integration of two or more of these skills, or other constructs of language ability. Equal weight may be placed on knowledge (understanding how the language works theoretically) and proficiency (ability to use the language practically), or greater weight may be given to one aspect or the other.

The history of language testing may have originated in the late nineteenth century testing of ESL at Cambridge and Oxford in England, but the earliest works in language assessment in the United States date back to the 1950s to the pioneering studies and test created by Robert Lado and David Harris. The earliest large scale assessments in the United States were referred to as the Michigan Tests, developed by the English Language Institute at the University of Michigan, now known as Michigan Language Assessment, and the Test of English as a Foreign Language (TOEFL) developed by Educational Testing Service (ETS), Princeton, New Jersey.

The English Language Institute at the University of Michigan (Michigan Language Assessment) was established in 1941 and was the first of its kind in the United States. Charles Fries, Director of ELI, and Robert Lado, Director of Testing at ELI, were determined to put foreign language teaching and testing on a "scientific" footing. The first test launched in 1946 was the Lado Test of Aural Comprehension. Approximately 10 years later, a full suite of tests had been assembled: "an English language test battery", which was administered to incoming foreign students at Michigan and other universities and was known as the Michigan English Language Assessment Battery. In 1953, the ELI also developed the ECPE (Examination for the Certificate of Proficiency in English) exam, under contract to the United States Information Agency, for use abroad. The Michigan Tests continue to support international student and professional mobility and include the Michigan English Test (MET), which is offered worldwide at testing centers and remotely.

TOEFL was launched in 1961 and was designed to assess the English language ability of students applying for admission to U.S. and Canadian colleges and universities. This test, which is used widely around the world, is still in use although it is now only available in the internet-based format (now called the TOEFL iBT).

Many tests from other companies, universities and agencies compete for this market: iTEP (International Test of English Proficiency), the Canadian English Language Proficiency Index Program (CELPIP) Test, the Pearson Language Test's Pearson Test of English (PTE), Michigan Language Assessment exams include Michigan English Test (MET), Examination for the Certificate of Competency in English (ECCE) and Examination for the Certificate of Proficiency in English (ECPE), and the British Council and the Australian IDP's International English Language Testing System (IELTS). In the United States, non-profit and other organizations such as the Center for Applied Linguistics, Washington, D.C., and Language Testing International, White Plains, NY have developed language tests that are used by many public and private agencies. Many universities too, like the University of California, Los Angeles, Teachers College, Columbia University, and the University of Illinois, Urbana-Champaign, have developed English (and other) language tests to assess the abilities of their students and teaching assistants. These language assessments are generally known as proficiency or achievement assessments. Other modern English language tests developed include The General English Proficiency Test (GEPT) in Taiwan, the College English Test in China, and the STEP Eiken in Japan. New technology has also made a presence in the field: Versant's English and Dutch assessments use phone technology to record the speaking and automated scoring of their speaking tests, and the ETS is currently experimenting with automated scoring of their writing tests.

The International Language Testing Association (ILTA) is one of the many organizations that organizes conferences, workshops, and a public forum for the discussion of important matters. ILTA's major annual conference is the Language Testing Research Colloquium. ILTA's Lifetime Achievement Award winners include: Alan Davies (UK), Lyle Bachman (US), Bernard Spolsky (Israel), John Clark (US), Charles Alderson (UK), Carol Chapelle (US), Elana Shohamy (Israel), Tim McNamara (Australia), Cyril Weir (UK), Dan Douglas (US), Cathie Elder (Australia), Jin Yan (China), Liz Hamp-Lyons (UK), and Antony John Kunnan (Indo-US).

Educational Testing Service, Princeton, New Jersey, the home of the TOEFL, offers an annual outstanding Doctoral Dissertation Award in Second or Foreign Language and the University of Cambridge, UK, also offers an annual outstanding master's degree Award in second language testing. In Europe, there are two organizations: the Association of Language Testers of Europe (ALTE) and the European Association for Language Testing and Assessment (EALTA). All of these associations have developed Codes of Ethics and Practice that all language assessment professionals are expected to adhere to.

There are many annual conferences on general or specific topics. Among the most important conferences is ILTA's official conference: the Language Testing Research Colloquium (LTRC), which has been held every year since 1978. In the last few years, it has been held in different parts of the world: Temecula, California, US (2004); Ottawa, Canada (2005); Melbourne, Australia (2006); Barcelona, Spain (2007); Hangzhou, China (2008), and Denver, Colorado (2009), Cambridge, UK (2010), Ann Arbor, Michigan (2011), Princeton, New Jersey (2012), and Seoul, South Korea (2013).