EXHIBIT 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

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We hereby consent to the incorporation by reference in the Registration Statement on Form S-8 (No. 333-275275) of NL Industries, Inc. of our report dated March 9, 2026 relating to the financial statements, which appears in this Form 10-K.

/s/ PricewaterhouseCoopers LLP

Dallas, Texas

March 9, 2026