[2][3][4] Originally designed by Northrop as a low-cost, low-maintenance fighter jet, the F-5 was intended for use by air forces that had limited resources and technical expertise.

In 1964, the Royal Canadian Air Force, searching for a replacement for both the conventional attack fighter CF-104 and the nuclear strike interceptor CF-101, proposed entering into a joint production agreement with the United Kingdom to build over 100 F-4 Phantom II (which the Royal Navy was eager to acquire) but this was rejected as too costly.

[5] In February 1965, Chief of Operational Readiness and a future CDS, Lieutenant-General Jean Victor Allard, evaluated four possible replacements: Northrop F-5, Grumman A-6 Intruder, Douglas A-4 Skyhawk and LTV A-7 Corsair II.

[6] While the Royal Canadian Navy wanted the A-4 Skyhawk, as a replacement for its carrier based McDonnell F2H Banshee, the only aircraft deemed "not suitable" was the F-5, and the A-7 Corsair was recommended.

[7] Nonetheless, Defense Minister Paul Hellyer "questioned the RCAF’s preoccupation with fighters generally, and he rejected the need for and the utility of the nuclear strike role specifically" and changed the requirements, thus "guaranteeing that the CF-5 be selected as the new tactical fighter, and that the RCAF was to adopt an affordable aircraft capable of performing a conventional attack role," even though he later wrote in his biography that the F-5 was “little more than a trainer with guns hung on it.”[8][9] In Canada, which had a mature aerospace industry, selection of the less sophisticated F-5 was a disappointment and "clearly unpopular" among those in the RCAF.

[10] Selected to provide a tactical support role, based in Canada but to relocate to Europe, CF-5 squadrons were also committed to NATO's northern flank to act as a rapid-deployment force.

In order to address complaints about long takeoff runs, the Canadair version featured a two-position nose landing gear; compressed it operated like the original, but extended (before takeoff) it raised the nose and thereby increased the angle of attack and increased lift.

A midair refueling probe was installed, Orenda-built General Electric J85-15 engines with 4,300 lbf (19 kN) thrust were used, and a more sophisticated navigation system was added.

[11] As part of the production sharing agreement between the Canadian and Dutch governments the centre fuselages for all but the first 31 aircraft were built by Fokker in the Netherlands.

Most surplus aircraft were sold to Turkey (most to Turkish Stars) and Venezuela (mix CF-5A and CF-5D - 18 in 1972, 2 new CF-5D in 1974 and 7 ex-RNAF NF-5A/B in 1990; all served with Grupo de Caza 12) or retained for spares support.

In 1991, after tensions between Colombia and Venezuela almost led to a conflict, the air force started yet another modernization program for the F-5s, called "Proyecto Grifo" (Project Gryphon).

In 1992, during the coup d'état attempt against president Carlos Andres Perez, 3 F-5s were lost to a rebel-operated OV-10 Bronco bombing Barquisimeto Air Base.

The fleet was equipped with inertial laser navigation systems (similar to those in Venezuelan F-16s), IFFs, HUDs, refueling probes and modernized engines with an estimated lifespan of 22 years.