8755 West Higgins Road, Suite 500

Chicago, Illinois 60631

December 2, 2020

Ms. Effie Simpson

Securities and Exchange Commission

Division of Corporation Finance

Office of Manufacturing

100 F Street

Washington, DC 20549

Re:    Littelfuse, Inc.

Form 10-K for the Fiscal Year Ended December 28, 2019

Filed February 21, 2020

Form 10-Q for the Period Ended September 26, 2020

Filed October 28, 2020

File No. 000-20388

Dear Ms. Simpson:

This letter is in response to the comment letter of the staff of the United States Securities and Exchange Commission (the “Commission”) dated November 20, 2020 (the “Comment Letter”) related to the Form 10-K for the Year Ended December 28, 2019 of Littelfuse, Inc. (the “Company”, “our” or “we”) filed February 21, 2020 and Form 10-Q for the Period Ended September 26, 2020 filed October 28, 2020.

For your convenience, we have set forth below the text of the comments contained in the Comment Letter in italicized type, followed by our response.

Form 10-Q for the Period Ended September 26, 2020

Management’s Discussion and Analysis of Financial Condition and Results of Operations

Results of Operations, page 29

1.We note that your discussions of the factors contributing to the fluctuations in your income statement line items between periods appear to often attribute the change “primarily” to several factors, “partially offset” by one or more factors. In future filings, to enhance an investor’s understanding, in addition to identifying the reasons for the change, please revise your discussions to quantify the impact attributable to each factor identified. Refer to SEC Release FR-72.

Response:

The Company reviewed SEC Release FR-72 and confirms, in future filings, in addition to identifying the reasons for the fluctuations in the Company’s income statement line items between periods, we will quantify the impact, as appropriate, for each factor identified.

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2.Similarly, we note your discussion of the changes in your gross profit and gross margins between periods. Given your ongoing actions to improve your cost structure, and the significance of changes in cost of sales on these two measures, please revise future filings to separately quantify and discuss the factors responsible for changes in the levels of cost of sales. Consider also discussing the impact of these changes in cost of sales on your segment results. Refer to SEC Release FR-72.

Response:

The Company reviewed SEC Release FR-72 and confirms, in future filings, we will separately quantify and discuss the factors responsible for changes in the levels of cost of sales when material to understanding changes in our gross profit and gross margins between periods. Additionally, we will consider discussing the impact of these changes in cost of sales in our segment results.

We further acknowledge that the Company is responsible for the adequacy and accuracy of the disclosures in our filing.

Please contact me if you have any questions regarding these matters at 773-628-0616.

Sincerely,

/s/ Meenal A. Sethna

Meenal A. Sethna
Executive Vice President and Chief Financial Officer

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