Exhibit 23(b)





               CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS

We consent to the reference to our firm under the caption "Experts" in the
Registration Statement (Form S-3) and related Prospectus of Aon Corporation for
the registration of 2,000,000 shares of its common stock and to the
incorporation by reference therein of our reports dated February 8, 2001, with
respect to the consolidated financial statements of Aon Corporation incorporated
by reference in its Annual Report (Form 10-K) for the year ended December 31,
2000 and the related financial statement schedules included therein, filed with
the Securities and Exchange Commission.




                                             /s/ERNST & YOUNG LLP




Chicago, Illinois
July 20, 2001