Yes, it's Valentine's Day. I suppose I'm dating myself (yet again) by mentioning that I can remember when it was known as St. Valentine's Day. Watch movies like Holiday Inn, or any story from that era that took place around this time of the year, and you'll hear it called that all the time. (Incidentally, read here to find out more about the real St. Valentine, who was martyred for the faith, and his association with love. HT Jimmy Akin.)
Nowadays, thanks to our slickly secular society, you seldom ever hear it referred to as St. Valentine's Day, except when talking about the famous massacre of the same name. And yet, a year or two ago, so great is our urge to completely erase from earshot anything that even smacks of religion, I heard a newscaster actually refer to the "Valentine's Day Massacre," so great is our urge to wipe out any possible popular mention of saints. Not only was this piece of PC historically incorrect (like it or not, the name St. Valentine's Day Massacre is a historical fact), it just doesn't sound right. It makes me wonder how long it'll be before we're celebrating March 17 simply as "Patrick's Day," and somebody's asking why they named a holiday after a pink starfish in a cartoon.
Speaking of Valentine's Day, AdoroTeDevote has a nice piece on some of the ways in which Valentine's Day could be celebrated, and why there are people out there who don't want to hear about it.