Here is the O Antiphon for today:
Dec. 22 - O Rex Gentium: “O King of all the nations, the only joy of every human heart; O Keystone of the mighty arch of man, come and save the creature you fashioned from the dust.” (cf. Isa 2:4; 9:7)
Also see my previous post, "What Are the O Antiphons?"
Pax Christi,
phatcatholic