The BMW 303 was a middle sized saloon produced by BMW in 1933 and 1934. It was the first BMW to use the 'kidney grill' which today is a hallmark of the company's models.

The 303 was also the first BMW to feature an inline-6 engine. The M78 six-cylinder 1182 cc engine was developed from the four-cylinder 788 cc engine used by the company's BMW 3/20 model. Although the engine had the same bore and stroke as the four, the engineers increased the bore spacing to allow for further increases in bore, and to provide for more crankshaft bearings.

The 303 used a version of the independent front suspension used on the 3/20, but used a live axle at the rear instead of the 3/20's swing axle.

Both saloons and cabriolets were manufactured. Top speed was 56 miles per hour (90 km/h).

Only 2300 BMW 303s were produced.

BMW 309

The BMW 309 was a development of the 303. A replacement for the BMW 3/20, the 309 was a 303 with a four-cylinder engine developed from the M78 six-cylinder engine used in the 303, with the bore increased from 56 mm (2.2 in) to 58 mm (2.3 in).

The 309 was manufactured from 1934 to 1936, with a total of 6,000 made.