Yes, a day trip to Byron Bay from Brisbane is a very popular and feasible option, though it makes for a long and active day. The drive typically takes between 2 to 2.5 hours each way via the M1, covering approximately 165 kilometers. If you depart Brisbane around 7:00 AM, you can arrive in Byron by mid-morning, leaving plenty of time to walk up to the Cape Byron Lighthouse—the easternmost point of the Australian mainland—and enjoy a few hours at Main Beach or Wategos. You can explore the eclectic boutiques and cafes in the town center before heading back to Brisbane in the late afternoon. While a car offers the most flexibility, there are also organized day-tour operators that provide round-trip transport and guided highlights. However, travelers should be mindful of the "school holiday" traffic and the fact that New South Wales (where Byron is located) often operates on a different daylight savings schedule than Queensland (Brisbane) during the summer, which can result in a one-hour time difference that might catch you off guard when planning your return.