More likely, it's the plug, plug wires, cap, or rotor.
Timing will affect all cylinders equally, so, instead of a miss, you'll get poor performance, poor fuel economy, or detonation from improperly set timing, but not a dead miss.
Try this:
Start the engine, and set it at a speed a little above idle.
Pull one plug wire at a time, noting any change in speed (it should slow down, and get rough). Replace the plug wire, and move to the next. The one that doesn't create a noticeable change in speed is the one that's causing the miss.
Now, evaluate the electrical components related to that one cylinder, starting at the plug, then the plug wire, then the distributor cap, then the rotor.
Fix, or replace, the bad part(s), and you should be back to plowin' before the sun gets too high.