Company: SPH
Filing Date: 2025-02-21
Form Type: 424B5
Source: 0001193125-25-030891
Chunk: 6

Company: SUBURBAN PROPANE PARTNERS LP
Filing Date: 2025-02-21
Form: 424B5
Chunk 6
---
 in or incorporated by reference under the heading “Risk Factors” on page 6 in this prospectus and in the documents incorporated by 
 reference into this prospectus and any free writing prospectus that we have authorized for use in connection with this offering.                                                                                               |

| Other Relationships | Affiliates of Wells Fargo Securities, LLC, J.P. Morgan Securities LLC and BofA Securities, Inc. are, as of the date of this prospectus, lenders under our credit facility, and affiliates of some or all of the Agents may in the future be lenders 
 under any new credit facility or any amendments or restatements of our existing credit facility and the Agents and/or their respective affiliates may from time to time hold our debt securities or other indebtedness.                             |

| New York Stock Exchange symbol | SPH. |

| Transfer Agent and Registrar | Computershare Trust Company, N.A. |

3

FORWARD-LOOKINGSTATEMENTS This prospectus and the information incorporated by reference in this prospectus contains forward-lookingstatements (“Forward-LookingStatements”) as defined in the Private Securities Litigation Reform Act of 1995, Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, relating to future business expectations and predictions, capital expenditures, strategic alternatives, project developments, and financial condition and results of operations of the Partnership. Some of these statements can be identified by the use of forward-lookingterminology such as “prospects,” “outlook,” “believes,” “estimates,” “intends,” “may,” “will,” “should,” “could,” “anticipates,” “expects” or “plans” or the negative or other variation of these or similar words, or by discussion of trends and conditions, strategies or risks and uncertainties. These Forward-LookingStatements involve certain risks and uncertainties that could cause actual results to differ materially from those discussed or implied in such Forward-LookingStatements (statements contained in this Prospectus identifying such risks and uncertainties are referred to as “Cautionary Statements”). The risks and uncertainties that could impact the Partnership’s results include, but are not limited to, the following:

| • |     | The impact of weather conditions on the demand for propane, renewable propane, fuel oil and other refined fuels, 
 natural gas, renewable natural gas (“RNG”) and electricity;                                                      |

| • |     | The impact of climate change and potential climate change legislation