Company: NOC
Filing Date: 2025-05-28
Form Type: 424B5
Source: 0001193125-25-129530
Chunk: 5

Company: NORTHROP GRUMMAN CORP /DE/
Filing Date: 2025-05-28
Form: 424B5
Chunk 5
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 provide related to hazardous and high risk operations, including the production and use 
 of such products, which subject us to various environmental, regulatory, financial, reputational and other risks |

| • |     | our ability appropriately to protect and exploit intellectual property rights |

| • |     | the adequacy and availability of, and ability to obtain, insurance coverage, customer indemnifications or other 
 liability protections                                                                                           |

| • |     | the future investment performance of plan assets, gains or losses associated with changes in valuation of                                                                                                         
 marketable securities related to our non-qualified benefit plans, changes in actuarial assumptions associated with our pension and other postretirement benefit plans and legislative or other regulatory actions 
 impacting our pension and postretirement benefit obligations                                                                                                                                                      |

| • |     | changes in business conditions that could impact business investments and/or recorded goodwill or the value of 
 other long-lived assets, and other potential future liabilities                                                |

You are urged to consider the limitations on, and risks associated with, forward-looking statements and not unduly rely on the accuracy of forward-looking statements. These forward-looking statements speak only as of the date of this prospectus supplement or, in the case of any document incorporated by reference, the date of that document. We undertake no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by applicable law. S-4

Summary

The following summary is provided solely for your convenience. It is not intended to be complete. You should read carefully this entire prospectus supplement, the accompanying prospectus and all the information included or incorporated by reference herein or therein, especially the risks discussed in the section titled “Risk factors” beginning on page S-8of this prospectus supplement and in the documents incorporated by reference herein.

Northrop Grumman Corporation

Northrop Grumman Corporation is a leading global aerospace and defense technology company. We deliver a broad range of products, services
and solutions to U.S. and international customers, and principally to the DoD and intelligence community. Our broad portfolio is aligned to support national security priorities and our solutions equip our customers with capabilities they need to
connect, protect and advance humanity.

We are a leading provider of space systems, military aircraft, missile defense, advanced weapons and long-range
fires capabilities, mission systems, networking and communications, strategic deterrence systems, and breakthrough technologies, such as advanced computing, microelectronics and cyber. We are focused on competing and winning programs that