The semi-bonneted original Comet was first shown in December 1947. While intended mainly for export, it was also sold in the home market. The wheelbase is 17.5 ft (5.3 m) and the gross weight 8.75 long tons (8,890 kg). A coach model seating 33, sharing the same front design, appeared in 1948. The cab was built by Briggs Motor Bodies and was shared with the Ford Thames ET6 and Dodge 100. Ford purchased Briggs in 1953, meaning Leyland (and Dodge) were forced to develop new cabs as shown on the Vanguards model below. The original engines were a 75 hp (56 kW) diesel or a 100 hp (75 kW) petrol unit; the petrol version was rarely seen in Britain.

In 1950 the diesel engine was updated to the new 5.76 litre Leyland O.350 unit, now with 90 hp (67 kW). Maximum weight was increased to 12 long tons (12,200 kg); models for tropical zones received a considerably lower rating. In 1955 the maximum power output was increased again, to 100 hp (75 kW) at 2200 rpm, as the new O.350 Mk. III engine replaced the previous version.

The bonneted model continued in production until 1958, although Australian models continued to use this cab into the early 1960s. This model also entered production in India after having received government approval in 1951. Ashok Motors, Ashok Leyland after 1954, manufactured it locally. The original front clip design remained in use into the early 1970s. Ashok Leyland proceeded to develop a simplified local cab design and continued to build the Comet into the 1990s.