UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ~~Form~~FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of ~~November 2023~~ June 24. Commission File Number 001-14928 ~~SANTANDER~~ ۲ Santander UK ~~PLC~~plc (Translation of registrant'’s name into English) 2 Triton Square, Regent’s Place, London NW1 3AN, England (Address of principal executive office) Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F. ☒Form 20-F ☒ ☐ Form 40-F ☐

913 ~~November~~June ~~2023 Santander~~2024 SANTANDER UK ~~Group~~PLC ~~Holdings~~AND ~~plc~~SANTANDER ~~& Santander~~ UK ~~plc Directorate~~GROUP ~~change Santander~~HOLDINGS UKPLC ~~today~~– ~~announces~~BOARD ~~the~~CHANGE David ~~appointment~~Gledhill of– ~~Angel~~Appointment ~~Santodomingo~~ as ~~Chief~~Independent ~~Financial~~Non-Executive ~~Officer.~~Director ~~Angel~~Santander ~~will~~UK ~~join~~plc ~~the~~and ~~executive~~Santander ~~team,~~UK ~~reporting~~Group toHoldings ~~CEO~~plc ~~Mike~~announce ~~Regnier,~~the ~~and~~appointment ~~will~~of ~~assume~~David ~~his~~Gledhill as ~~role~~an ~~in December,~~Independent inNon-Executive ~~anticipation~~Director ofwith ~~receipt~~effect offrom ~~regulatory~~1 ~~approval~~September 2024. HeDavid ~~will~~is ~~also~~a ~~be appointed~~ Non-Executive Director of ~~Santander~~Singapore UKAirlines ~~Group~~and ~~Holdings~~the ~~plc~~Institute ~~and~~of ~~Santander~~Systems ~~UK plc~~Science, ~~effective from the later date of~~National ~~receipt~~University of ~~regulatory~~Singapore ~~approval~~with orsignificant ~~1 January 2024. Angel has nearly 40 years’~~ experience in financial services, ~~and~~retail ~~has~~banking ~~worked~~and ~~within the Santander Group~~digital ~~for nearly 20 years~~transformation. He ishas ~~currently~~held ~~Group~~various ~~Head~~senior ofleadership ~~Strategy~~roles ~~and~~in ~~Chief of Staff to~~ the ~~Executive~~financial ~~Chair of~~services ~~Banco Santander~~industry, ~~Ana Botín. He joined the Santander~~ including Group inChief ~~2005~~Information asOfficer and Head of ~~International Developments~~Technology and ~~Asset~~Operations ~~Management~~at ~~and~~DBS Bank in ~~2014 was appointed CFO and Investor Relations Officer~~Singapore, ~~Santander~~spending ~~S.A.~~over ~~(Brazil)~~a ~~before~~decade ~~returning to Spain and his current role~~ in ~~2023. Angel~~that ~~replaces Duke Dayal who had held the~~ role ~~of CFO at Santander UK since 2019~~. Santander UK ~~CEO~~Chairman, ~~Mike~~William ~~Regnier~~Vereker said: “I am delighted to welcome ~~Angel~~David to ~~Santander~~the UKBoards ~~as our~~of ~~CFO~~Santander UK. He brings ~~with him~~ a ~~huge~~breadth ~~amount~~ of ~~valuable~~ experience ~~from Group,~~ which will beadd ~~of enormous~~value ~~benefit~~ to usour asplans weto ~~roll~~transform ~~out~~ our business ~~new~~and ~~Group~~I ~~operating~~am ~~model~~looking ~~announced~~forward ~~last~~to ~~month~~working with him.” ~~Angel~~ - ~~Santodomingo~~Ends ~~said:~~- For ~~“After~~media 18enquiries, ~~years~~please ~~working~~contact: Miranda ~~across~~Seymour ~~different~~Head ~~parts~~ of ~~the~~Media ~~Group,~~Relations Imediarelations@santander.co.uk 07860 ~~am excited~~857999 toPaul beSharratt ~~joining~~Head ~~the~~of UKInvestor ~~business~~Relations ir@santander.co.uk 07715 I087 ~~look~~829 Additional ~~forward~~information toabout ~~working~~Santander ~~closely~~UK ~~with the Board~~ and ~~the~~Banco ~~management team~~Santander Santander ~~and~~UK ~~helping~~is toa ~~shape~~financial ~~the~~services ~~future~~provider ofin the ~~bank.” -~~UK ~~Ends~~that ~~- Editor’s~~offers ~~notes Photo~~a ~~available~~wide onrange ~~request. Angel~~of ~~Santodomingo~~personal –and ~~career~~commercial financial ~~history Angel~~products ~~has~~and ~~held~~services. aAt ~~number~~31 ofDecember ~~positions~~2023, ~~across~~the ~~financial~~bank ~~services~~had ~~firms~~around in19,800 ~~Spain~~employees and ~~Latin America.~~serves ~~Before~~around ~~joining~~14 ~~the~~million ~~Santander~~active ~~Group~~customers, in7 ~~2005,~~million hedigital ~~was~~customers ~~the~~via ~~President~~a ofnationwide ~~CFA~~444 ~~Spain~~branch network, ~~a professional~~telephone, ~~association~~mobile ~~representing~~and ~~investment~~online ~~professionals~~banking. inSantander ~~Spain~~UK ~~and~~is ~~Andorra. Angel~~subject ~~joined~~to the ~~Santander~~full ~~Group~~supervision ~~as Head~~ of ~~International~~the ~~Developments~~FCA and ~~Asset~~the ~~Management~~PRA in ~~2005,~~ ~~and most recently held~~ the ~~position~~UK. Santander ofUK ~~Group~~plc ~~Head~~customers’ ofeligible ~~Strategy~~deposits ~~and~~are ~~Chief~~protected ofby ~~Staff to~~ the ~~Executive~~ ~~Chair~~FSCS ofin the UK. Banco Santander (SAN SM, ~~Ana~~STD ~~Botín.~~US, HeBNC ~~has~~LN) ~~held~~is a ~~number~~leading ofcommercial ~~Board~~bank, ~~positions~~founded in ~~companies~~ in1857 ~~Brazil~~ and ~~Uruguay. Santander~~headquartered in UKSpain isand aone ~~financial~~of ~~services~~the ~~provider~~largest banks in the UKworld ~~that~~by ~~offers~~market acapitalization. ~~wide~~The ~~range~~group’s ofactivities ~~personal and~~are ~~commercial~~consolidated ~~financial~~into ~~products~~five ~~and~~global ~~services.~~businesses: AtRetail 30& ~~June~~Commercial ~~2023~~Banking, ~~the~~Digital ~~bank~~Consumer ~~had around 19~~Bank,~~400~~ ~~employees~~Corporate & ~~and~~Investment ~~serves~~Banking ~~around 14 million active customers~~(CIB), 7Wealth ~~million~~Management ~~digital~~& ~~customers~~Insurance ~~via~~and aPayments ~~nationwide~~(PagoNxt ~~445 branch network, telephone, mobile~~ and ~~online banking~~Cards). ~~Santander~~This UKoperating model isallows ~~subject~~the bank to ~~the~~better ~~full~~leverage ~~supervision~~its ofunique ~~the FCA~~combination ~~and~~of ~~the~~global ~~PRA~~scale inand ~~the~~local UKleadership. Santander aims UKto ~~plc~~be ~~customers’~~the ~~eligible~~best ~~deposits~~open ~~are~~financial ~~protected~~services byplatform ~~the~~providing ~~FSCS in~~services ~~the UK.~~ to

~~Banco~~ SIGNATURE Pursuant ~~Santander~~to ~~(SAN~~the ~~SM,~~requirements ~~STD~~of ~~US,~~the ~~BNC~~Securities ~~LN)~~Exchange isAct aof ~~leading commercial bank~~1934, ~~founded in 1857 and headquartered in Spain. It has a meaningful presence in 10 core markets in~~ the ~~Europe,~~registrant ~~North America~~has ~~and~~duly ~~South~~caused ~~America~~this ~~regions,~~report ~~and~~to isbe ~~one~~signed ofon ~~the~~its ~~largest~~behalf ~~banks in the world~~ by ~~market capitalization. Santander aims to be~~ the ~~best open financial services platform providing services to individuals~~undersigned, ~~SMEs, corporates,~~thereunto ~~financial institutions~~duly ~~and governments~~authorized. SANTANDER ~~The~~UK ~~bank’s~~PLC (Registrant) Date ~~purpose~~14 isJune ~~to help people and businesses~~2024 ~~prosper~~By /s/ inJohn ~~a simple, personal and fair way. Santander is building a more responsible bank and has made~~Mills a(Signature)* Company ~~number~~Secretary * ofPrint ~~commitments~~the toname ~~support this objective, including raising €220 billion in green financing between 2019~~ and ~~2030.~~title Inunder the ~~first~~signature ~~half~~ of ~~2023, Banco Santander had €1.25 trillion in total funds, 164~~the ~~million~~signing ~~customers, 9,000 branches and 212,000 employees~~officer. ~~For further information: mediarelations@santander.co.uk~~

~~SIGNATURES Pursuant~~2 ~~to the requirements~~ of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized. SANTANDER UK PLC Dated: 9 November 2023 By / s / John Mills Company Secretary 4

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