John J. Diehl Jr. Disbarred by Missouri Supreme Court

MO Courts Attorney Discipline

Filed January 29th, 2026

Detected March 18th, 2026

Summary

The Missouri Supreme Court has disbarred attorney John J. Diehl Jr., accepting his voluntary surrender of his law license. This action terminates his right to practice law in the state and requires compliance with disbarment procedures. A fee of $2,000.00 is also assessed.

View original document View source feed page

What changed

The Missouri Supreme Court has issued an order disbarring John J. Diehl Jr., accepting his voluntary surrender of his law license due to admitted misconduct. The order officially cancels his license, strikes his name from the roll of attorneys, and terminates his right to practice law in Missouri. Petitioner Diehl is required to comply with Rule 5.27 regarding procedures following a disbarment order, including delivering his license or submitting an affidavit of loss. Additionally, a fee of $2,000.00 is assessed, and costs are taxed to the Petitioner.

This action has immediate and severe consequences for John J. Diehl Jr., effectively ending his legal career in Missouri. Other legal professionals in the state should be aware of the disciplinary process and the importance of adhering to the Rules of Professional Conduct. Compliance with the specific post-disbarment procedures outlined in Rule 5.27 is mandatory. The assessed fee and costs represent a financial penalty associated with the disciplinary action.

What to do next

Comply with Rule 5.27 regarding procedures following disbarment
Deliver law license or submit affidavit of loss
Pay $2,000.00 fee to the Clerk of the Court

Penalties

Disbarment, license cancellation, name stricken from roll of attorneys, $2,000.00 fee, costs taxed to Petitioner.

Source document (simplified)

Supreme Court of Missouri
en banc

29 January 2026 Supreme Court of Missouri Case # SC101274 In re: John J. Diehl Jr., MBE # 42400 ORDER Petitioner, John J. Diehl Jr., having filed in this Court a motion to voluntarily surrender his license to practice law in this state; and
Petitioner having admitted misconduct in violation of this Court’s Rules of Professional Conduct; and
The Court having received the Chief Disciplinary Counsel’s report and recommendation filed herein;
The Court, thus advised, now orders that the surrender of the license of John J. Diehl Jr. be accepted and that said license be canceled.
It is further ordered that the name of John J. Diehl Jr. be stricken from the roll of attorneys in this state, that he be disbarred, and that his right and license to practice law in this state is hereby terminated.
It is further ordered that the said John J. Diehl Jr. comply in all respects with Rule 5.27 – Procedure Following a Disbarment or Suspension Order. In particular, Petitioner shall deliver his license to practice law or submit an affidavit attesting his license is lost.
Fee pursuant to Rule 5.19(k) in the amount of $2,000.00 payable to the Clerk of this Court to the credit of the Advisory Committee.
Cost taxed to Petitioner. Day - to – Day

W. Brent Powell Chief Justice Note: To view any specific rule provisions cited in this order, please visit the pages for Supreme Court of Missouri Rule 4 and Rule 5. Please be aware the versions of the rules available online are those currently in effect and may have changed since this order issued.