$1,000,000,000 Xylem Inc. $500,000,000 5.200% Senior Notes due 2033$500,000,000 5.450% Senior Blue Notes due 2036 We are offering $1,000,000,000 aggregate principal amount of notes, consisting of $500,000,000 aggregate principal amount of our 5.200% Senior Notes due 2033, which we refer toas the “2033 notes” and $500,000,000 aggregate principal amount of our 5.450% Senior Notes due 2036, which we refer to as the “ 2036 blue notes.” We refer to both series of the notesoffered hereby collectively as the “notes.” We will pay interest on the notes semi-annually on June 1 and December 1 of each year, commencing on December 1, 2026. The 2033 notes will bear interest at the rate of 5.200% perannum and the 2036 blue notes will bear interest at the rate of 5.450% per annum. The 2033 notes will mature on June 1, 2033 and the 2036 blue notes will mature on June 1, 2036. We may redeem some or all of the notes of either series at any time and from time to time at the applicable redemption price described under “Description of Notes—OptionalRedemption.” If we experience a change of control triggering event, as defined under the indenture governing the notes, each holder of note may require us to repurchase some or all of itsnotes at a purchase price equal to 101% of the aggregate principal amount of the notes repurchased, plus any accrued and unpaid interest up to, but not including, the repurchase date. See“Description of Notes—Repurchase Upon Change of Control Triggering Event.” The notes will be our senior unsecured obligations and rank equally with our other unsecured and unsubordinated indebtedness. The notes will be issued only in minimumdenominations of $2,000 and integral multiples of $1,000 in excess thereof. The notes are new issues of securities with no established trading markets. We do not intend to apply to list either series of the notes on any securities exchange or to have the notes ofeither series quoted on any automated quotation system. As described in “Use of Proceeds,” we will allocate an amount equal to the net proceeds from the sale of the 2036 blue notes to a portfolio of Eligible Blue Projects (as defined in “Useof Proceeds”). Pending allocation for such purposes, we intend to hold and/or invest the balance of net proceeds not yet allocated to the portfolio of Eligible Blue Projects in our treasuryliquidity portfolio, or in cash or other short-term and liquid instruments. Investing in the notes involves risks. You should carefully read and consider therisk factorsincluded in this prospectus supplementbeginning on page S-9 and included in our periodic reports and other information that we file with the Securities and Exchange Commissionbefore you invest in the notes. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the notes or determined that this prospectussupplement or the accompanying prospectus is accurate or complete. Any representation to the contrary is a criminal offense. Prospectus Supplement Table of Contents ABOUT THIS PROSPECTUS SUPPLEMENT This document is in two parts. The first part is this prospectus supplement, which describes the terms of the offering of the notes. The second partis the accompanying prospectus dated August3, 2023, which we refer to as the “accompanying prospectus.” The accompanying prospectus contains a We are responsible for the information contained in or incorporated by reference in this prospectus supplement, the accompanying prospectus andin any related free writing prospectus we prepare or authorize. We have not, and the underwriters have not, authorized anyone to give you any otherinformation, and neither we nor the underwriters take responsibility for any other information that others may give you. The notes are offered globallyfor sale only in those jurisdictions where it is lawful to make such offers. We are not, and the underwriters are not, making an offer of these securities inany jurisdiction where the offer or sale is not permitted. Persons outside the United States who receive this prospectus supplement and theaccompanying prospectus should inform themselves about and observe any such restrictions. This prospectus supplement and the accompanyingprospectus do not constitute, and may not be used in connection with, an offer to sell or the solicitation of an offer to buy (i)by any person in any Before you invest in the notes, you should carefully read the registration statement (including the exhibits thereto) of which this prospectussupplement and the accompanying prospectus form a part, this prospectus supplement, the accompanying prospectus and the documents incorporated by Unless otherwise indicated or the context otherwise requires, references in this prospectus to “Xylem,” the “Company,” “we,” “us,” and “our”refer to Xylem Inc. and its consolidated subsidiaries. WHERE YOU CAN FIND MORE INFORMATION We file annual reports on Form 10-K, quarterly reports on Form 1