Mark Henry Lyon
On the New York attorney register since 2012 · office in Washington, DC
PlainAttorney’s reading of the public register file, not a court record.
- Registration No.
- 4978748
- Admitted
- 2012 · Second Department
- Status
- Currently registered
- Next registration
- Oct 2028
Mark Henry Lyon is currently registered on the New York attorney register file of Sep 29, 2026. Admitted in 2012 in the Second Department, with an office in Washington, DC; next registration due Oct 2028. The status is the same in all 3 files we hold.
What this status means on the register
On the register, “Currently registered” means Mark Henry Lyon has filed the biennial registration the court system requires; the next one is due in Oct 2028.
- Currently registered unchanged
- Currently registered unchanged
- Currently registered the first file we hold
Source: NY Office of Court Administration, attorney registration file (data.ny.gov, dataset eqw2-r5nb), downloaded Sep 29, 2026; the Jul 3, 2026 and Aug 6, 2026 files for the history.
Others who list this employer on the register
95 other attorneys list Williams & Connolly LLP or one of its other names as their employer on the register; 36 of them were admitted before 2012, and 95 of the 96 give an office in Washington, DC. The 5 whose admission is closest to 2012, earliest first:
| Attorney | Admitted | Status |
|---|---|---|
| Melissa Bradshaw Collins | 2012 | Due to re‑register |
| Nicholas Garber Gamse | 2012 | Currently registered |
| Benjamin Nicholas Hazelwood | 2012 | Due to re‑register |
| Adam Joshua Podoll | 2012 | Currently registered |
| Stephen Lewis Wohlgemuth | 2012 | Currently registered |
Source: NY Office of Court Administration, attorney registration file (data.ny.gov, dataset eqw2-r5nb), downloaded Sep 29, 2026; employer spellings merged (methodology).
Where this record sits on the register
Mark Henry Lyon studied at Mississippi College School of Law. 21 of its 54 living graduates on the register were admitted in the 2010s, as Mark Henry Lyon was.
- Same law school
- 54living graduates; 92.6% registered (current or due), against 87.1% overall
- Office in Washington, DC
- 12,527living registrants (outside New York State)
Of the 12,527 living registrants with an office in Washington, DC, 7,350 were admitted before 2012 and 4,692 after.
Source: NY Office of Court Administration, attorney registration file (data.ny.gov, dataset eqw2-r5nb), downloaded Sep 29, 2026; living registrants only.
Questions this record leads to
- Everyone who lists Williams & Connolly LLP96 on the register, 36 of the others admitted before 2012; 95 of the 96 give an office in Washington, DC.
- Mississippi College School of Law graduates on the register54 living, 92.6% registered.
- New York-admitted attorneys in Washington, DC12,527 living registrants give an office there.
- Admitted in 20129,632 people admitted in 2012 are on the register, 2,535 of them through the Second Department.
- Every registration that reads “Currently registered”286,911 on the register file of Sep 29, 2026, by decade of admission.
- What a New York lawyer may chargeThe court rules on fees, retainers and fee disputes, each cited.
How to confirm it officially
For a statement of Mark Henry Lyon’s standing, contact the Attorney Registration Unit of the NY Office of Court Administration (nycourts.gov/attorneys), or ask the Appellate Division, Second Department, which admitted Mark Henry Lyon in 2012. The register places the office outside New York, so a complaint would go to that department’s grievance committee (22 NYCRR 1240.7(a)(2)).
This page reads the register file of Sep 29, 2026, and the court system’s own search can be newer; the register shows only the current value, so a suspension that ended before the files we hold, or a censure, leaves no trace here (Appellate Division decisions are published through the court system’s Law Reporting Bureau).