Unsurprisingly, the LS500h shares its hybrid drivetrain with the closely related LC500h coupe. Both models feature a new Multi-Stage Hybrid drivetrain with 264kW of total system power that uses a traditional automatic transmission instead of the company's usual e-CVT setup.
Under the skin there's a naturally aspirated 3.5-litre V6 with 220kW of power and 350Nm of torque, which is augmented by two electric motors. Drive goes to the rear wheels via a four-speed automatic transmission that's been tuned to deliver the feel of a 10-speed gearbox.
According to Lexus, the LS500h is able to sprint from 0-100km/h in 5.4 seconds. Intriguingly, the company has yet to provide fuel economy figures for the hybrid LS sedan.
Compared to the LS500, which features a 310kW/600Nm 3.5-litre twin-turbo V6, the LS500h has 46 fewer kilowatts, and is slower to 100km/h by 0.6 seconds.
Lexus says that the LS500h is capable of driving in electric-only mode at speeds up to 140km/h.
Available features in the new LS range include a 12.3-inch infotainment screen, 24-inch colour head-up display, active noise cancellation, a 3D surround sound Mark Levinson audio setup, hand-pleated door trim, artisan glass trim pieces, rear-seat extending ottoman, and 28-way power front seats.
Like the conventionally powered LS500 that was unveiled at this year's Detroit motor show, the LS500h sits a 3125mm wheelbase, and is 5235mm long, 1450mm tall, and 1900mm wide.
Offered with just one wheelbase length, the new LS is longer, wider and lower than today's long wheelbase LS sedan.
The LS500 and LS500h will both make their Australian debut in the first quarter of 2018.