Company: WTFCN
Filing Date: 2025-05-09
Form Type: 424B5
Source: 0001104659-25-046769
Chunk: 76

Company: WINTRUST FINANCIAL CORP
Filing Date: 2025-05-09
Form: 424B5
Chunk 76
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 or Recognised Bodies (as such terms are defined in the Financial Services and Markets Regulations 2015 (“FSMR”)), or (c) are persons to whom an invitation or inducement to engage in investment activity (within the meaning of section 18 of FSMR) in connection with the issue or sale of any securities may otherwise lawfully be communicated or caused to be communicated (all such persons together being referred to as “relevant persons”). This prospectus supplement and the accompanying prospectus are directed only at relevant persons and must not be acted on or relied on by persons who are not relevant persons. Any investment or investment activity to which this prospectus supplement and the accompanying prospectus relate are available only to relevant persons and will be engaged in only with relevant persons.

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### LEGAL MATTERS
The validity of the depositary shares offered hereby will be passed upon for Wintrust by Sidley Austin LLP, Chicago, Illinois. Certain legal matters related to the offering will be passed upon for the underwriters by Squire Patton Boggs (US) LLP, Cincinnati, Ohio.

### EXPERTS
The consolidated financial statements of Wintrust Financial Corporation appearing in Wintrust Financial Corporation’s Annual Report (Form 10-K) for the year ended December 31, 2024and the effectiveness of Wintrust Financial Corporation’s internal control over financial reporting as of December 31, 2024 (excluding the internal control over financial reporting of Macatawa Bank Corporation) have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their reports thereon, which as to the report on the effectiveness of Wintrust Financial Corporation’s internal control over financial reporting contains an explanatory paragraph describing the above referenced exclusion of Macatawa Bank Corporation from the scope of such firm’s audit of internal control over financial reporting included therein and incorporated herein by reference. Such consolidated financial statements and Wintrust management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2024 (which did not include an evaluation of the internal control over financial reporting of Macatawa Bank Corporation) have been incorporated herein by reference in reliance upon such reports given on the authority of such firm as experts in accounting and auditing.

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### PROSPECTUS

### Wintrust Financial Corporation
<div align='center'>**Debt Securities, Common Stock, Preferred Stock, Depositary