Will I receive an honorable discharge after failing my tape test on my last drill in the Army National Guard?

SPC (Join to see), if the separation is only for "Failure to meet body fat standards", then you're a Chapter 18 separation (AR 635-200, Chapter 18). Chapter 18 separations will receive an honorable characterization if discharged (it could be uncharacterized if you have less than 180 days of active duty, but this doesn't apply to you).

Again, if it's ONLY for weight, then it will be honorable. However, if there is anything else, then you'll be administratively separated under that guidance and the characterization would be based on that action.

However, the larger comment is regarding your status. If this is the first failure, then you are put onto the unit weight control program. If you don't make satisfactory progress in six months, you could be separated. If you come off the program and go back on within 12 months, you could be separated.

I say 'could' and not 'will' because it's mandatory to submit the separation action, but it's not mandatory to separate the Soldier. Your leadership could recommend that you be retained, but the decision is up to the separation authority (usually that will be the Brigade/O6 commander).

You should have been formally counseled by your leadership about your failure and had all this laid out.

Up to your command!, Normally not a problem, but.

Did you fail one previously within the last 12 months? As in, 12 months ago (or less) you failed a HT/WT Tape, then passed, then failed again? If this is your first one and no previously failed tape test within the last 12 months, then you will not be chaptered and will receive the Honorable Discharge. However, if this is FAIL #1, then the clock starts now. If you pass and then fail again within the next 12 months, then you can/will be chaptered. That being said, if you meant that this FAIL occurred on your absolute very last BTA of your obligated service requirement, then you shouldn't stress about not getting an Honorable.