How many Boeing 737-100s, the first version, were ever built?

The 737-100 launched the first generation of the family, the "Original" series, announced in February 1965 alongside the 737-200. Boeing defined it based on market research pointing to demand for a fifty-to-sixty-seat aircraft for routes between 50 and 1,000 miles. Lufthansa became the launch customer on 19 February 1965, when it signed an order for 21 aircraft. With that contract it became the first non-US airline to launch a new Boeing jet. The close collaboration with that airline ended up stretching the original 60-seat jet to a capacity of up to 100 passengers.

Only 30 units of this first version were produced. Of these, one was the prototype and 29 were production aircraft. Lufthansa received the bulk of them, with a total of 22 deliveries. Malaysia-Singapore Airlines took five aircraft and Avianca two. The last of the 30 built was delivered to Malaysia-Singapore Airlines in October 1969.

The first -100 rolled out of the factory on 17 January 1967 and made its maiden flight on 9 April 1967. The FAA issued type certificate A16WE, clearing the 737-100 for commercial flight, on 15 December 1967. The model entered service in February 1968.