Filed pursuant to Rule 433
Relating to Preliminary Prospectus Supplement dated November 29, 2018 to
Prospectus dated September 25, 2018
Registration Statement Nos. 333-227514-01 and 333-227514
Aon Corporation
TERM SHEET
$350,000,000 4.500% SENIOR NOTES DUE 2028

Issuer:	 	Aon Corporation	
		
Securities:	 	4.500% Senior Notes due 2028	
		
Guarantor:	 	Aon plc	
		
Legal Format:	 	SEC Registered	
		
Amount:	 	$350,000,000	
		
Ranking:	 	Senior Unsecured	
		
Expected Ratings*:	 	Moody’s Investors Service: Baa2
Standard & Poor’s: A-
Fitch: BBB+	
		
Trade Date:	 	November 29, 2018	
		
Settlement Date (T+2):	 	December 3, 2018	
		
Maturity Date:	 	December 15, 2028	
		
Reference Treasury:	 	3.125% due November 15, 2028	
		
Reference Treasury Price and Yield:    	 	100-25; 3.033%	
		
Reoffer Spread to Treasury:	 	+150 bps	
		
Reoffer Yield:	 	4.533%	
		
Coupon:	 	4.500%	
		
Denominations:	 	$2,000 and multiples of $1,000	
		
Interest Payment Dates:	 	Semi-annually in arrears on June 15 and December 15, beginning on June 15, 2019	
		
Price to Public:	 	99.735%	
		
Proceeds to Issuer (before expenses):	 	$347,147,500	
		
CUSIP / ISIN:	 	037389 BB8 / US037389BB82	
		
Optional Redemption:	 	Prior to September 15, 2028, we may redeem all of the Notes at any time or some of the Notes from time to time at a redemption price equal to the greater of 100% of the principal amount of the Notes being redeemed and a make whole using a discount rate of the Reference Treasury plus 25 basis points. On or after September 15, 2028 (three months prior to maturity), we may redeem any or all of the Notes at a redemption price equal to 100% of the principal amount of the Notes being redeemed. In the event of certain changes in respect of taxes applicable to the Notes or the Guarantee of the Notes, we may redeem the Notes in whole at any time at a redemption price equal to 100% of the principal amount of the Notes being redeemed. See “Description of the Securities—Optional Redemption” and “Description of the Securities—Optional Tax Redemption” in the preliminary prospectus supplement for more information.	

			
		
Joint Book-Running Managers:	  	J.P. Morgan Securities LLC
Morgan Stanley & Co. LLC
HSBC Securities (USA) Inc.	
		
Co-Managers:	  	Aon Securities Inc.
ING Financial Markets LLC
UniCredit Capital Markets LLC
U.S. Bancorp Investments, Inc.	
		
Conflicts:	  	Aon Securities Inc. is an indirect wholly owned subsidiary of Aon Corporation. This offering is subject to, and will be conducted in compliance with, the requirements of Rule 5121 of the Financial Industry Regulatory Authority, Inc. (“FINRA”) regarding a FINRA member firm distributing the securities of an affiliate.	
* An explanation of the significance of ratings may be obtained from the rating agencies. Generally, rating agencies base their ratings on such material and information, and such of their own investigations, studies and assumptions, as they deem appropriate. The rating of the notes should be evaluated independently from similar ratings of other securities. A credit rating of a security is not a recommendation to buy, sell or hold securities and may be subject to review, revision, suspension, reduction or withdrawal at any time by the assigning rating agency.
The issuer and the guarantor have filed a registration statement, including a prospectus, with the SEC for the offering to which this communication relates. Before you invest, you should read the prospectus in that registration statement and other documents the issuer has filed with the SEC for more complete information about the issuer, the guarantor and this offering. You may get these documents for free by visiting EDGAR on the SEC Web site at www.sec.gov. Alternatively, the Joint Book-Running Managers in the offering will arrange to send you the prospectus if you request it by contacting J.P. Morgan Securities LLC collect at 1-212-834-4533, Morgan Stanley & Co. LLC toll-free at 1-866-718-1649, and HSBC Securities (USA) Inc. toll-free at 1-866-811-8049.