ADTRAN delivered solid first quarter results with revenue of $286.1 million, up 15.5% year-over-year, and non-GAAP operating margin of 6.9%, up 3% year-over-year. This quarter also marked a meaningful step in our growth strategy as we showcased our expanding portfolio addressing cloud and AI infrastructure connectivity. Optical Networking Solutions revenue was $97.3 million in the first quarter, up 24% year-over-year. Operators across all geographies are expanding wholesale optical capacity to support growing demand for cloud connectivity and higher bandwidth services, reflecting a broad-based trend.
In Europe, high-risk vendor replacement initiatives continue to add to that demand. With growing strength among our cloud and hyperscaler customers and a positive outlook across our service provider base, we expect our Optical Networking Solutions revenue to build throughout the year. Access and Aggregation Solutions revenue was $90.5 million in the first quarter, up 2% year-over-year and 14% sequentially, driven by broad-based strength across the U.S. Subscriber Solutions revenue was $98.2 million in the first quarter, up 22% year-over-year.
Demand remains healthy, supported by continued investment in Fiber to the home, multi-gig Wi-Fi 7, and Carrier Ethernet applications. Stepping back from the details for the quarter, I want to take a moment to talk about our business and the market dynamics that continue to drive demand for our solutions. Service providers are investing across transport, access, and subscriber platforms to scale their networks for long-term demand and improved reliability. Beyond our core service provider business, we continue to see meaningful opportunities to further accelerate growth by expanding our presence in both cloud providers and enterprise customers.