In Las Vegas, live-money blackjack tournaments (as opposed to those played with tournament chips that have no face value) are very rare. There are one-off events, whether invitational or open-to-all, but we haven't heard of many (if any) lately.
In fact, it seems that blackjack tournaments in general are a dying breed, at least if mini-tournaments are used as a gauge. We last updated our mini-tourney listings in July and found regular events taking place at 12 properties. Calls a couple of days ago revealed that the number has been decimated to less than half, with only five casinos now hosting weekly blackjack tournaments. Aliante Station and Suncoast -- two of the recent casualties -- both mentioned rumors that their events might be reinstated at some unspecified future date, but for now the only tournaments we know of are at Arizona Charlie's Boulder, Cannery, Longhorn, M Resort, Rampart, and the Silver Nugget.
You can find details of times, buy-ins, prize structure etc. in our Tournament section. Just select "blackjack" from the drop-down menu and be sure to check the "mini" box to pull up recurring events. If you play one, be sure to revisit our listings and add your rating/review of the event for the edification of other potential players.
And by the way, while many players lament the demise of live-money tournaments, this is actually a very good development for players. The reason is that blackjack-tournament strategy frequently requires bold and strange plays, such as doubling down on hard 17. While making such plays can enhance your chances of winning a tournament, it also costs you a lot in real money when the bets are live. Busting on these plays with non-negotiable chips costs you no more than the fixed amount of your entry fee.