In French, the words that were borrowed from Latin and contained the Latin diphthong written as œ now generally have é or è; but œ is still used in some non-learned French words, representing open-mid front rounded vowels, such as œil ("eye") and sœur ("sister").

It is used in the modern orthography for Old West Norse and is used in the International Phonetic Alphabet to represent the open-mid front rounded vowel.

In French, œ is called e dans l'o [ə dɑ̃ lo], which means e in the o (a mnemotechnic pun used first at school, sounding like (des) œufs dans l'eau, meaning eggs in water) or sometimes o et e collés, (literally o and e glued) and is a true linguistic ligature, not just a typographic one (like the fi or fl ligatures), reflecting etymology.

In Canadian French, the names o-e liés ("linked O and E") or lettre double œ (where O and E are pronounced separately for clarity) are used officially.

[2] Œ is most prominent in the words mœurs ("mores"), cœur ("heart"), chœur ("choir"), sœur ("sister"), œuf ("egg"), bœuf ("beef", "steer"), œuvre ("work") and œil ("eye"), in which the digraph œu, like eu, represents the sound [œ] (in other cases, like plurals œufs ("eggs") and bœufs ("steers"), it stands for [ø]).

Modern American English spelling usually substitutes œ with e, so diarrhœa has become diarrhea, although there are some exceptions, such as phoenix.

The œ ~ oe ~ e is traditionally pronounced as "short Ĕ" /ɛ/, as "long Ē" /iː/, or as an (unrounded) unstressed vowel.

These three Modern-English values interchange with one another in consistent ways, just as do the values within each of the sets from the other vowel-spellings that at the Middle English stage likewise represented non-diphthongs — except for, as was recognised particularly in certain positions by Dobson[3]:  495  a tendency whereby There are a few words that English has recently borrowed from contemporary French.

The likes of fœ̯tid, though superficially exceptional here, do indeed belong here in this category because the counting properly includes also final -e that has gone silent since Middle English (and therefore has been left out by some spellings) in those situations where speakers before the -e's demise, such as Chaucer (who did not drop it in rhymes), would have had the -e as an intrinsic part of the word (rather than as just a suffix) — save for its regularly disappearing where followed with no pause by a word beginning with a vowel or sometimes /h/.

As less-circumstantial evidence (than this word's modern short Ĕ /ɛ/) that it contained the final -e, consider both the spelling of its earliest attestation in English recorded by the NED,[4] within "It maketh to blister both handes, & feet, out of which issueth foetide, and stinckinge water."

A common exception is the French word Œuvre[7] and its compounds (e.g. Œuvreverzeichnis[8] It remains used in Swiss German, especially in the names of people and places.

[10] The Uralic Phonetic Alphabet (UPA) includes U+1D14 ᴔ LATIN SMALL LETTER TURNED OE.

Œ and œ/ɶ were omitted from ISO-8859-1 (as well as derived standards, such as IBM code page 850), which are still widespread in internet protocols and applications.