Companies in Maryland
1M companies registered in Maryland, sourced from official business registers and enriched with industry, size, location and contact data. Below: the largest companies by reported revenue, and how the Maryland business base breaks down by industry and headcount.
Part of the United States company directory.
Rankings
Largest companies in Maryland
By reported (actual) revenue, updated September 2026. Public-sector entities are excluded.
| # | Company | Industry | City | Revenue (USD) | Employees |
|---|---|---|---|---|---|
| 1 | Lockheed Martin Corporation | Manufacture of air and spacecraft and related machinery | Bethesda | $75B | 123,000 |
| 2 | Constellation Energy Generation, LLC | Electric power generation, transmission and distribution | Baltimore | $25.5B | 15,339 |
| 3 | Constellation Energy Corporation | Electric power generation, transmission and distribution | Baltimore | $25.5B | 15,339 |
| 4 | Marriott International, Inc. | Hotels and similar accommodation | Bethesda | $25.1B | 414,000 |
| 5 | Allegis Group, Inc. | Activities of employment placement agencies | Hanover | $14.9B | 85,000 |
| 6 | The Whiting-Turner Contracting Company | Construction of residential and non-residential buildings | Baltimore | $13.8B | 4,560 |
| 7 | THE JOHNS HOPKINS HEALTH SYSTEM CORPORATION | Hospital activities | Baltimore | $9.6B | 13,000 |
| 8 | The Hopkins Johns University | Tertiary education | Baltimore | $9.5B | 37,600 |
| 9 | Medstar Health, Inc. | Other human health activities | Columbia | $9B | 33,000 |
| 10 | T. Rowe Price Group, Inc. | Trusts, funds and similar financial entities | Baltimore | $7.3B | 7,773 |
| 11 | Teksystems, Inc. | Temporary employment agency activities | Hanover | $6.9B | 2,900 |
| 12 | Host Hotels & Resorts, Inc. | Fund management activities | Bethesda | $6.1B | 162 |
| 13 | Host Hotels & Resorts, L.P. | Hotels and similar accommodation | Bethesda | $6.1B | 162 |
| 14 | Kaiser Foundation Health Plan of The Mid-Atlantic States, Inc. | Non-life insurance | Rockville | $5.9B | 9,873 |
| 15 | Montgomery County, MD | Administration of the State and the economic and social policy of the community | Rockville | $5.6B | 7,400 |
| 16 | University of Maryland Medical System Corporation | Hospital activities | Baltimore | $5.6B | 12,000 |
| 17 | Baltimore Gas and Electric Company | Electric power generation, transmission and distribution | Baltimore | $5.2B | 3,383 |
| 18 | Under Armour, Inc. | Manufacture of other outerwear | Baltimore | $5B | 14,400 |
| 19 | Ciena Corporation | Manufacture of communication equipment | Hanover | $4.8B | 9,080 |
| 20 | Agnc Investment Corp. | Fund management activities | Bethesda | $3.5B | 54 |
| 21 | Amergis Healthcare Staffing, Inc. | Temporary employment agency activities | Columbia | $3.3B | 5,100 |
| 22 | United Therapeutics Corporation | Manufacture of pharmaceutical preparations | Silver Spring | $3.2B | 1,400 |
| 23 | Sinclair, Inc. | Motion picture, video and television programme production activities | Hunt Valley | $3.2B | 7,100 |
| 24 | Blue Owl Credit Income Corp. | Business and other management consultancy activities | Lutherville-Timonium | $3.1B | 324 |
| 25 | ESAB Corporation | Manufacture of other machine tools | North Bethesda | $2.8B | 10,300 |
Top 25 by revenue reported to the register. Companies filing no revenue figure are not ranked, whatever their size.
Lockheed Martin Corporation leads Maryland at $75B in reported revenue, from Bethesda.
Coverage
Companies by industry in Maryland
The industries holding the most companies, by NACE activity code.
Ranked by number of companies. Each record carries its NACE code alongside SIC and NAICS, so the same segment can be pulled in any of the three schemes.
Browse these directories
Other business support service activities n.e.c. is the largest activity in Maryland, with 62,892 companies.
Distribution
Company size
By number of employees.
10,112 companies have no disclosed headcount (excluded from the chart).
89% of Maryland companies with a disclosed headcount fall in the 1-4 employee band.
Data coverage
What a Maryland record carries
Share of the state's companies holding each contact field.
25%
with a website
45%
with a phone number
16%
with an email address
Counted against the 1M companies in Maryland. Firmographics — industry, size, address, status — are present on every record.
FAQ
Companies in Maryland — frequently asked questions
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