What was the first Apple Watch model with cellular connectivity?

The first Apple Watch model with cellular connectivity was the Apple Watch Series 3.

Introduced in September 2017, Apple Watch Series 3 added an LTE-capable version with an electronic SIM, or eSIM. This allowed the watch to share the iPhone's phone number and perform selected connected tasks without being continuously near the phone.

With cellular service enabled, users could make and receive calls, send messages, use Siri, stream Apple Music, and access data while away from their iPhone. The cellular model was sold alongside a GPS-only version, so not every Series 3 watch included LTE.

Earlier Apple Watch models, including Series 2, could use Wi-Fi and Bluetooth but did not have built-in cellular service. The Apple Watch Series 4 followed in 2018 and also offered cellular versions, but it was not the first. Apple Watch SE models came later and likewise cannot be the answer.