Prepared Remarks:

Operator

Good morning, and thank you for holding. Welcome to Aon plc's second quarter 2022 conference call. [Operator instructions] I would also like to remind all parties that this call is being recorded. If anyone has an objection, you may disconnect your line at this time.

It is important to note that some of the comments in today's call may constitute certain statements that are forward-looking in nature as defined by the Private Securities Reform Act of 1995. Such statements are subject to certain risks and uncertainties that could cause actual results to differ materially from historical results or those anticipated. Information concerning risk factors that could cause such differences are described in the press release covering our second quarter 2022 results as well as having been posted on our website. Now, it is my pleasure to turn the call over to Greg Case, CEO of Aon plc.

Thank you, sir. You may begin.

Greg Case -- Chief Executive Officer

Thank you, and good morning, everyone. Welcome to our second quarter conference call. I'm joined by Christa Davies, our CFO; and Eric Andersen, our president. As in previous quarters, we posted a detailed financial presentation on our website.

We begin by expressing our deepest appreciation for our colleagues. Their extraordinary dedication to delivering results for clients, bringing the best of Aon across geographies and solution lines, is inspiring. And their passion and commitment are reflected in the highest-ever colleague engagement recorded in our latest full survey. In the second quarter, our colleagues delivered excellent results, demonstrating continued momentum and progress against our key financial metrics.

Organic revenue growth was 8% in Q2 and year to date, on top of 11% in prior-year quarter, consistent with our ongoing financial guidance of mid-single-digit or greater organic revenue growth. This top-line strength translated into an adjusted operating margin of 26.2% in the quarter, up 40 basis points from last year, and adjusted EPS growth of 15%, demonstrating the strength of our Aon United strategy and Aon business services platform. Turning to revenue. Commercial risk delivered 7% organic revenue growth, driven by ongoing strong retention and renewals, highlighting the strength of our core business and strength from areas of investment like CoverWallet within digital client solutions.