Ah, Horace. One of the greatest of the poets. His Odes will live as long as there are humans to appreciate thought, speech, and verse. He also, thankfully, expressed some Epicurean insights with great beauty and depth of feeling. Although that doesn't necessarily make him an Epicurean, in several respects he was (as he jestingly says in Epistle 4) "a swine in the herd of Epicurus".
I have translated into English the dozen or so of his Odes that I find to be most consistently Epicurean. Here, Horace emphasizes the brevity of life and the importance of keeping a tranquil mind, limiting one's desires, being happy with little, living unknown, and plucking the day. These are quite simply gorgeous expressions of something close to Epicureanism.
Yet gorgeous poems do not an Epicurean make. Horace admits that he is not interested in the topics of epic poetry (war, contest, ambition, etc.) and prefers to write about convivial parties and the romantic "wars" between men and women (Odes I.5). Although Epicurus would have agreed about shunning the agonistic pursuits of war and politics, he was also uninterested in feasts, romance, and the like. There is also little to no evidence that Horace was versed in the fundamentals of Epicurean philosophy: accepting the validity of sense perception, engaging in the study of what is natural, developing one's reason, steering clear of all enculturation, disbelieving in gods who meddle in human affairs, rejecting fate, eliminating unnatural and unnecessary desires from one's life, focusing on the few things that are truly natural and necessary.
Indeed, you could even think of Horace as a more measured, steady version of Catullus; Horace wasn't as vulgar or as flighty, but his priorities were quite similar: love, feasts, poetry, and in general "la dolce vita" (hey, they were both proto-Italians, right?).
Nevertheless that very measured, steady experience of life leads me to think that Horace absorbed more of Epicurus than Catullus did. The influence of Epicurus (and his poetic interpreter Lucretius) is more prominent and widespread in the poetry of Horace, whether it be his Odes, his Epodes, or his Satires. Although this influence is not consistently expressed, that fact should come as no great surprise, since most writers and thinkers and regular human beings accept intellectual influences from many sources (in the case of Horace, as of Montaigne, those influences include both Stoicism and ancient Cynicism). I am merely thankful that Horace wrote a few handfuls of truly immortal poems under the influence of Epicurus. After all, we can't say the same for any other poet in history, except Lucretius.