it's a small world

Used to express surprise at meeting an acquaintance or discovering a personal connection in a distant place or an unexpected context.
- 1880–1881, Thomas Hardy, chapter I, in A Laodicean; or, The Castle of the De Stancys. A Story of To-day. […], volume III, London: Sampson Low, Marston, Searle & Rivington, […], published 1881, →OCLC, book the fifth (De Stancy and Paula), page 40:
  “I have met my young photographer,” said De Stancy, cheerily. “What a small world it is, as every busybody truly observes! I am wishing he could take some views for us as we go on; but you have no apparatus with you, I suppose, Mr. Dare?”

phrase used when meeting an acquaintance or personal connection in an unexpected place or context

Catalan: el món és un mocador (literally “the world is a handkerchief”)
Chinese:
Mandarin: 好巧 (hǎo qiǎo)
Finnish: maailma on pieni
French: le monde est petit (fr)
German: die Welt ist klein, wie klein die Welt ist, die Welt ist ein Dorf (de) (literally “the world is a village”)
Hungarian: kicsi a világ
Italian: il mondo è piccolo, com'è piccolo il mondo, come è piccolo il mondo
Japanese: 世間は広い様で狭い (せけんはひろいようでせまい, seken wa hiroi yō de semai), 世界は狭い (せかいはせまい, sekai wa semai), 世間は狭い (せけんはせまい, seken wa semai)
Mari:
Eastern Mari: тӱня изи (tüńa izi)
Polish: jaki ten świat mały
Russian: мир те́сен (mir tésen, literally “the world is narrow”)
Spanish: el mundo es un pañuelo (literally “the world is a handkerchief”)
Swedish: världen är liten
Tagalog: ang liit ng mundo
Thai: โลกกลม
Ukrainian: яка Земля кругла (jaka Zemlja kruhla, literally “how round is the Earth”), тісний світ (tisnyj svit)

English