Below you can see the front view size comparison of Olympus E-M5 III and Sony A77 II. Olympus E-M5 III is clearly the smaller of the two cameras. Its body is 18mm narrower, 19mm shorter and 31mm thinner than Sony A77 II.
Olympus E-M5 III vs Sony A77 II - Front View
Olympus E-M5 III vs Sony A77 II - Top View
The chart below depicts how two cameras compare with average dimensions of the cameras in their class.
Camera Size Comparison
Select Two Cameras for Size Comparison