- 1). Click on the apple icon in the upper-left corner of your screen and select "About This Mac."
- 2). Click on the "More Info" button in the middle of the pop-up window. The System Profiler application will launch.
- 3). Scroll down in the System Profiler window and click on the "Network" category heading.
- 4). Click on the network adapter that you want to find the MAC address of. The MAC address for each adapter is located under the "Ethernet" section in the System Profiler information window.
Source...