I am often looking for these symbols and can’t find them. So here they are for English language Mac keyboards, in a handy blog format. They all use the Option key.
Note: The Option key is not the Command key, which is marked with ⌘ (looped square) symbol. Rather, the Option key is between Control and Command on many (most?) Mac keyboard. These key combinations won’t work a numerical keypad; you have to be using the main part of the keyboard.
The case of the letter/key pressed with the Option key matters. For example, Option+v is the root √ and Option+V (in other words, Option+Shift+v) is the diamond ◊. Another example: Option+7 is the paragraph ¶ and Option+& (that is, Option+Shift+7) is the double dagger ‡. You may simply copy/paste the symbols, if that’s more convenient.
These key combinations should work in most modern Mac applications, and be visible in most typefaces. No guarantees. Your mileage may vary.
ó Ó Option+e then letter (acute)
ô Ô Option+i then letter (circumflex)
ò Ò Option+` then letter (grave)
õ Õ Option+n then letter (tilde)
ö Ö Option+u then letter (umlaut)
å Å Option+a or Option+A (a-ring)
ø Ø Option+o or Option+O (o-slash)
æ Æ Option+’ or Option+” (ae ligature)
œ Œ Option+q or Option+Q (oe ligature)
ﬁ Option+% (fi ligature)
ﬂ Option+^ (fl ligature)
ç Ç Option+c or Option+C (circumflex)
ß Option+s (double-s)