The Scot had secured fifth on the grid at Silverstone but his car came in 1.5kg underweight in post-qualifying scrutineering.
Even with a mandatory fuel sample on board, the car weighed only 641.5 kg - which is 0.5 kg below the weight limit.
After the FIA drained the car of fuel, it was found it weighed just 640kg, two kilogrammes under the limit.
With a 0.5kg tolerance accepted for the scales' accuracy, it was ruled that the car was 1.5kg underweight.
After the matter was referred to the race stewards, it was decided that the team had been in breach of the regulations and di Resta was thrown out of the results.
He can now start the British GP from the back of the grid.
Force India is considering whether to appeal, as it is understood the missing weight relates to di Resta rather than the car. Driver and car weights are combined under Formula 1 rules.