We present optical spectroscopy in the range 3300-7400A for a total of 52 planetary nebulae in the Large Magellanic Cloud (LMC) and 18 in the Small Magellanic Cloud (SMC). Together with the object from the first (1991ApJS...75..407M) and second (1991ApJS...76.1085M) papers, we now have accurate emission-line intensities for a total of 147 nebulae in the Magellanic Clouds. This sample contains a large selection of objects of low luminosity, with measurements of line intensities down to ~10% of H{beta}. Brighter objects have line intensities measured down to ~2% of H{beta}. Agreement with other authors is generally very good, especially for lines greater than approximately 10% of H{beta}. Reddening estimates from Balmer line ratios have been determined: unreddened and reddened line intensities are tabulated.