This is Vegas, so why not? The Clark County Marriage Bureau issues licenses year-round, open Sunday through Thursday 8am to midnight, and 24 hours on Friday, Saturday, and legal holidays. Walk-ins are welcome — no appointment needed.
The license costs around $100 and takes only a few minutes to process. You'll need a valid government-issued photo ID and to know your Social Security numbers. There's no waiting period in Nevada, so you can pick up a license and head straight to a chapel.
The bureau is housed in the Clark County Government Center downtown, about a mile from the Strip. It's a no-frills civil office, not a romantic setting — but it's the necessary first stop before any of the city's famously kitschy wedding chapels can do their thing.