ژوئن (به فرانسوی: Juin) یا جون (به انگلیسی: June) ششمین ماه سال میلادی در گاهشمار ژولینی و گاهشمار گریگوری است و یکی از چهار ماه ۳۰ روزهٔ سال است. اووید شاعر رومی، در چکامههایش برای نام ژوئن، دو ریشه آوردهاست: نخستین آن یونو (juno)، خدایگان رومی و همسر ژوپیتر است که هم ردیف هرا خدایگان یونانی در افسانههای یونان باستان است. دوم: گفتهاست که این نام از واژهٔ لاتین iuniores به معنی «جوانترها» گرفته شده که در برابر maiores به معنی «بزرگترها» یا «پیرترها» قرار میگیرد. اووید بر این باور بود که ریشهٔ ماه مه، ماه پیش از ژوئن، از واژهٔ maiores گرفته شدهاست.
نه در سالهای معمولی و نه در سالهای کبیسه هیچ ماهی وجود ندارد که با همان روزی از هفته آغاز شود که ژوئن آغاز میشود. ماه مه و ژوئن تنها دو ماهی اند که از این ویژگی برخوردارند. ژوئن در همان روزی از هفته به پایان میرسد که مارس به پایان میرسد.
در نیمکرهٔ شمالی ژوئن بلندترین روزهای سال و در نیمکرهٔ جنوبی کوتاهترین روزها را دارد. از نظر فصلی ژوئن در نیمکرهٔ شمالی برابر با دسامبر در نیمکرهٔ جنوبی است و برعکس. در نیمکرهٔ شمالی ۱ ژوئن آغازگر تابستان است و در نیمکرهٔ جنوبی آغازگر زمستان.
چون نام ژوئن یا جون از نام خدایگان یونو (juno) (یا هرا) گرفته شدهاست و یونو خدای ازدواج و زوجهای ازدواج کرده بود، برخی این مطلب را به فال نیک میگیرند و آن را عاملی مؤثر در خوشبختی میدانند برای همین در این ماه بیشترین شُمار ازدواج دیده میشود.
افسانهای ایسلندی میگوید که اگر در ۲۴ ژوئن، برهنه در شبنمهای سحرگاه تنی به آب بزنی، آنگاه تا هنگامهٔ پیری در ساحل چنین خواهی کرد.
June is the sixth month of the year in the Julian and Gregorian calendars, the second of four months to have a length of 30 days, and the third of five months to have a length of less than 31 days. June contains the summer solstice in the Northern Hemisphere, the day with the most daylight hours, and the winter solstice in the Southern Hemisphere, the day with the fewest daylight hours (excluding polar regions in both cases). June in the Northern Hemisphere is the seasonal equivalent to December in the Southern Hemisphere and vice versa. In the Northern Hemisphere, the beginning of the traditional astronomical summer is 21 June (meteorological summer begins on 1 June). In the Southern Hemisphere, meteorological winter begins on 1 June.
No other month starts on the same day of the week as June in any year. This month and May are the only two months to have this property. June ends on the same day of the week as March in all years and starts on the same day of the week as February of the following year. In years immediately before common years, June begins on the same day of the week as March and November and ends on the same day of the week as August and November of the following year. In years immediately before leap years, June begins on the same day of the week as August and ends on the same day of the week as May of the following year. In common years, it begins on the same day of the week as September and December of the previous year and, in leap years, April and July of the previous year. In common years, June ends on the same day of the week as September of the previous year and in leap years, it ends on the same day of the week as April and December of the previous year. In years before common years, June 
At the start of June, the sun rises in the constellation of Taurus; at the end of June, the sun rises in the constellation of Gemini. However, due to the precession of the equinoxes, June begins with the sun in the astrological sign of Gemini, and ends with the sun in the astrological sign of Cancer.
Etymology and history
The Latin name for June is Junius. Ovid offers multiple etymologies for the name in the Fasti, a poem about the Roman calendar. The first is that the month is named after the Roman goddess Juno, the goddess of marriage and the wife of the supreme deity Jupiter; the second is that the name comes from the Latin word iuniores, meaning "younger ones", as opposed to maiores ("elders") for which the preceding month May (Maius) may be named. Another source claims June is named after Lucius Junius Brutus, founder of the Roman Republic and ancestor of the Roman gens Junia.
In ancient Rome, the period from mid-May through mid-June was considered inauspicious for marriage. Ovid says that he consulted the Flaminica Dialis, the high priestess of Jupiter, about setting a date for his daughter's wedding, and was advised to wait till after June 15. Plutarch, however, implies that the entire month of June was more favorable for weddings than May.
Certain meteor showers take place in June. The Arietids takes place May 22 to July 2 each year, and peaks on June 7. The Beta Taurids June 5 to July 18. The June Bootids take place roughly between 26 June and 2 July each year.
Ancient Roman observances
Under the calendar of ancient Rome, the festival of Ludi Fabarici took place on May 29 – June 1, Kalendae Fabariae took place on June 1, the Festival to Bellona took place on June 3, Ludi Piscatorii took place on June 7, and Vestalia took place from June 7 – June 15. A Rosalia was held on June 20. The Secular Games were held roughly every 100 years in either May or June. These dates do not correspond to the modern Gregorian calendar.
Events in June
Non-Gregorian observances, 2019
(All Baha'i, Islamic, and Jewish observances begin at the sundown prior to the date listed, and end at sundown of the date in question unless otherwise noted.)
Moveable observances, 2020
By other date
First Monday: June 1
First Wednesday: June 3
First Friday: June 5
First Saturday: June 6
First Sunday: June 7
Second Monday: June 8
Second Thursday: June 11
Second Saturday: June 13
Second Sunday: June 14
Third Week: June 14–20
Monday after the second Saturday: June 15
Third Friday: June 19
Third Saturday: June 20
Summer Solstice in the Northern Hemisphere: June 20
Winter Solstice in the Southern Hemisphere: June 20
Saturday between June 20–25: June 20
Saturday nearest Summer Solstice: June 20
Third Sunday: June 21
Monday Nearest to June 24: June 21
Last Thursday: June 25
Friday following Third Sunday: June 26
Last Saturday: June 27
Last Sunday: June 28
Fixed Gregorian observances