The information in this preliminary pricing supplement is not complete and may be changed. Preliminary Pricing SupplementSubject to Completion: Dated May 28, 2026 Auto-Callable Contingent Coupon Barrier NotesLinked to the Common Stock of Southwest AirlinesCo.,Due June 2, 2028 Pricing Supplement dated May __, 2026 to the Prospectusdated December 20, 2023, the Prospectus Supplementdated December 20, 2023 and the Product SupplementNo. 1B dated July 22, 2025 Royal Bank of Canada Royal Bank of Canada is offering Auto-Callable Contingent Coupon Barrier Notes (the “Notes”) linked to the performanceof the common stock of Southwest Airlines Co. (the “Underlier”).Contingent Coupons— If the Notes have not been automatically called, investors will receive a Contingent Coupon on a quarterly Coupon Payment Date at a rate of at least 13.10% per annum (to be determined on theTrade Date) if the closing value of the Underlier is greater than or equal to the Coupon Threshold (50% of theInitial Underlier Value) on the immediately preceding Coupon Observation Date. You may not receive anyContingent Coupons during the term of the Notes.Call Feature— If, on any quarterly Call Observation Date, the closing value of the Underlier is greater than or equal to the Initial Underlier Value, the Notes will be automatically called for 100% of their principal amountplusthe Contingent Coupon otherwise due. No further payments will be made on the Notes.Contingent Return of Principal at Maturity— If the Notes are not automatically called and the Final UnderlierValue is greater than or equal to the Barrier Value (50% of the Initial Underlier Value), at maturity, investors willreceive the principal amount of their Notesplusthe Contingent Coupon otherwise due. If the Notes are notautomatically called and the Final Underlier Value is less than the Barrier Value, at maturity, investors will receiveshares of the Underlier that will likely be worth significantly less than the principal amount of their Notes and couldbe worth nothing.Any payments on the Notes are subject to our credit risk.The Notes will not be listed on any securities exchange.CUSIP:78015QXS5 Investing in the Notes involves a number of risks. See “Selected Risk Considerations” beginning on page P-7 of this pricing supplement and “Risk Factors” in the accompanying prospectus, prospectus supplement andproduct supplement.None of the Securities and Exchange Commission (the “SEC”), any state securities commission or any other regulatory body has approved or disapproved of the Notes or passed upon the adequacy or accuracy of this pricing supplement. Anyrepresentation to the contrary is a criminal offense. The Notes will not constitute deposits insured by the Canada DepositInsurance Corporation, the U.S. Federal Deposit Insurance Corporation or any other Canadian or U.S. governmentalagency or instrumentality. The Notes are not bail-inable notes and are not subject to conversion into our common sharesunder subsection 39.2(2.3) of the Canada Deposit Insurance Corporation Act.Per NoteTotal Price to public(1)Underwriting discounts and commissions(1)Proceeds to Royal Bank of Canada(1) We or one of our affiliates may pay varying selling concessions of up to $17.50 per $1,000 principal amount of Notes inconnection with the distribution of the Notes to other registered broker-dealers. Certain dealers who purchase the Notesfor sale to certain fee-based advisory accounts may forgo some or all of their underwriting discount or selling concessions.The public offering price for investors purchasing the Notes in these accounts may be between $982.50 and $1,000.00 per$1,000 principal amount of Notes. See “Supplemental Plan of Distribution (Conflicts of Interest)” below.The initial estimated value of the Notes determined by us as of the Trade Date, which we refer to as the initial estimated value, is expected to be between $920.00 and $970.00 per $1,000 principal amount of Notes and will be less than thepublic offering price of the Notes. The final pricing supplement relating to the Notes will set forth the initial estimated value.The market value of the Notes at any time will reflect many factors, cannot be predicted with accuracy and may be lessthan this amount. We describe the determination of the initial estimated value in more detail below. RBC Capital Markets, LLC KEY TERMS The information in this “Key Terms” section is qualified by any more detailed information set forth in this pricingsupplement and in the accompanying prospectus, prospectus supplement and product supplement. Issuer:Underwriter:Minimum Investment:Underlier: Royal Bank of Canada RBC Capital Markets, LLC (“RBCCM”) $1,000 and minimum denominations of $1,000 in excess thereof The common stock of Southwest Airlines Co. (1)The closing value of the Underlier on the Trade Date (2)50% of the Initial Underlier Value (rounded to two decimal places) (3)A number of shares of the Underlier equal to $1,000divided byt