Prepared Remarks:

Operator

Good morning and thank you for holding. Welcome to Aon plc's first 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 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 first 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.

Greg Case -- Chief Executive Officer

Thank you and good morning, everyone. Welcome to our first 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'd like to start by acknowledging the tremendous work of our colleagues across the firm. They continue to exhibit remarkable leadership, supporting clients in a challenging environment. We also want to thank our colleagues for their inspiring support of our team, their families and others who have been impacted by the Russian war in Ukraine. This is a tragic example of increasing global volatility, adding to the challenges that face organizations and individuals every day, including continued effects of COVID-19, especially in Asia; inflation; climate change; capital availability; and connected impact to supply chains, intellectual property, workforce resilience and retirement readiness.

In this environment, helping our clients protect and grow their businesses, support their employees, their communities and their stakeholders has never been more important. Turning to financial performance. Our team delivered an excellent first quarter and start to the year with 8% organic revenue growth, an increase from a strong prior year performance of 6% in Q1 2021. This top line strength translated to a 38% adjusted operating margin, an increase of 60 basis points and 13% adjusted EPS growth, demonstrating the power of our Aon Business Services platform to drive sustainable margin expansion as well as support growth.