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                                         December 15, 2020

VIA EDGAR

Ms. Deborah L. O’Neal

Division of Investment Management

Securities and Exchange Commission

100 F Street, NE

Washington, D.C. 20549

Re: Post-Effective Amendment No. 129 to the Registration Statement

on Form N-1A of BlackRock Liquidity Funds (the “Trust”) on behalf of

its series, FedFund (File Nos. 2-47015 and 811-2354)

Dear Ms. O’Neal:

On behalf of the Trust, we herewith transmit for filing, under the Securities Act of 1933, as amended (the “Securities Act”), and the Investment Company Act of 1940, as amended (the “1940 Act”), Post-Effective Amendment No. 129 (the “Amendment”) to the Trust’s Registration Statement on Form N-1A (the “Registration Statement”) on behalf of FedFund (the “Fund”).

The Amendment is being filed pursuant to Rule 485(b) under the Securities Act and it is proposed that the Amendment become effective on December 15, 2020.

The Amendment is being filed for the purpose of (i) completing the information required to be provided in the Registration Statement and (ii) making certain other non-material changes which the Fund deemed appropriate.

The Amendment also includes interactive data format risk/return summary information in Inline XBRL that mirrors the risk/return summary information in the Amendment.

We have reviewed the Amendment and represent to the Securities and Exchange Commission that, to our knowledge, such Amendment does not contain disclosure that would render it ineligible to become effective pursuant to Rule 485(b).

The Amendment also contains the Trust’s responses to the telephonic comments provided by Ms. Deborah L. O’Neal of the staff (the “Staff”) of the Securities and Exchange Commission (the “Commission”) on November 5, 2020 regarding the Trust’s Post-Effective Amendment No.

Sidley Austin (NY) LLP is a Delaware limited liability partnership doing business as Sidley Austin LLP and practicing in affiliation with other Sidley Austin partnerships.

December 15, 2020

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127 to its Registration Statement filed with the Commission on September 28, 2020 pursuant to Rule 485(a) under the Securities Act. The Staff’s comments are described below and have been summarized to the best of our understanding. We have discussed the Staff’s comments with representatives of the Trust. The Trust’s responses to the Staff’s comments are set out immediately under the restated comment. Unless otherwise indicated, defined terms used herein have the meanings set forth in the Registration Statement.

Prospectus

Comment 1:    Please provide the completed fee table and expense examples and performance information for Mischler Financial Group Shares of the Fund a week prior to the effectiveness of the Fund’s registration statement.

Response:    The completed fee table and expense examples and performance information for the Fund’s Mischler Financial Group Shares were provided supplementally to the Staff on December 8, 2020.

Comment 2:    In the fee table relating to Mischler Financial Group Shares of the Fund, a footnote explains that BlackRock Advisors, LLC, as investment manager, has contractually agreed to waive fees and/or reimburse ordinary operating expenses in order to keep combined Management Fees and Miscellaneous/Other Expenses (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses) from exceeding a certain amount. Please discuss in correspondence whether any waivers or reimbursements pursuant to this contractual agreement can be recouped by BlackRock Advisors, LLC in subsequent periods.

Response:    BlackRock Advisors, LLC may not “recoup” any waivers or reimbursements under this contractual agreement.

Comment 3:    The Staff notes that the Fund’s principal risks are listed in alphabetical order. Please re-order the principal risks to prioritize the risks that are most likely to adversely affect the Fund.

Response: The Trust has considered the Staff’s comment and has determined to keep the order of the risk factors in alphabetical order. The Trust also notes that it has included the following disclosure in the sections of the Fund’s Mischler Financial Group Shares prospectus entitled “Fund Overview—Key Facts about FedFund—Principal Risks of Investing in the Fund” and “Details About the Fund—Investment Risks”:

December 15, 2020

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“The order of the below risk factors does not indicate the significance of any particular risk factor.”

*    *    *    *    *    *     * *    * *

Please do not hesitate to contact me at (212) 839-5511 if you have comments or if you require additional information regarding the Trust’s Registration Statement.

Respectfully submitted,

/s/    Douglas E. McCormack

Douglas E. McCormack

cc: Tricia Meyer

John A. MacKinnon

Jesse C. Kean