The Surface Book 2 is a 2-in-1 convertible laptop developed by Microsoft as part of its Surface line of personal computers. Released on November 16, 2017, it improved upon its predecessor, the original Surface Book, with enhanced performance, expanded hardware options, and introduction of a larger 15-inch model alongside the original 13.5-inch. In addition to functioning as a traditional laptop, the Surface Book's detachable touchscreen display allows it to be used as a standalone tablet or reattached in reverse for a convertible "Studio" mode. The device supports full touch and stylus input. The Surface Book 2 was succeeded by the third-generation Surface Book 3 in May 2020, and Microsoft officially ended firmware and driver updates on May 30, 2023, marking the end of official support.

The Surface Book 2 features a full-body magnesium alloy construction. The device comes in two distinct portions: a tablet that contains the CPU, storage, wireless connectivity and touchscreen, and a hardware keyboard base that contains a high-performance mobile GPU, supported by its own active cooling system.

The device contains two USB 3.0 Gen-1 ports, a USB-C port, 3.5 mm headphone jack, full-sized SD card slot, and two Surface Connect ports (one of which is always occupied by the keyboard base for communication between the two hardware portions, unless the tablet is detached from the base). The front-facing camera contains an infrared sensor that supports login using Windows Hello.

From a hardware perspective, this device marks Microsoft's first time to provide USB-C natively in any Surface device, also supporting USB-C Power Delivery. It was the only Surface computer equipped with USB-C until Microsoft's introduction of the Surface Go, in August 2018.

Surface Book 2 models ship with a pre-installed 64-bit version of Windows 10 Pro and a 30-day trial of Microsoft Office 365. Windows 10 comes pre-installed with Mail, Calendar, People, Xbox (app), Photos, Movies and TV, Groove, and Microsoft Edge. With Windows 10 the Tablet mode is available when the base is detached from the device. In this mode, all windows are opened full-screen and the interface becomes more touch-centric.

The Surface Book 2 is backward-compatible with all accessories of its direct predecessors, such as the Surface Dock, Surface Dial and Surface Pen. The device's native pen computing capabilities are based on N-trig technology Microsoft acquired in 2015, but major improvements were made to reduce input latency, add tilt support, and capture up to 4096 levels of pressure sensitivity. Following the device's general public launch, Microsoft has also published a series of software updates that further improved the device's palm rejection and pen computing accuracy.

The Surface Book 2 received broadly positive reviews, often compared favorably to Apple's MacBook Pro lineup. Most reviews applauded the Surface Book 2's keyboard for offering a class-leading 1.55 mm of key travel, significant performance improvement, well-controlled thermals, and new hinge - now redesigned and built as one singular component that increased device rigidity, improved overall docking reliability, and reduced screen wobble.

Other improvements include an improved IR camera that activates faster and supports enhanced anti-spoofing Windows Hello facial recognition, a faster solid-state drive with full drive encryption from first-boot, a built-in TPM chip, and two new cooling systems (for the CPU and GPU) that produce less high-pitched noise. The finger scoop has also been reshaped to avoid breaking the glass screen when the lid is being closed, which is a problem its predecessor suffered.