It found only 9% of employees without qualifications had any training in the last three months, compared to 38% of graduates.
More than three-quarters (76%) of staff without qualifications said they favoured the right to request paid time off to train, with seven out of ten employees saying they would like this as a legal request.
Brendan Barber, TUC general secretary, said: "Workers have a great zeal to learn new skills. The enthusiasm shown by people on low incomes, those with few or no qualifications and part-time workers, shows that while those who need most training have the biggest appetite to learn, they receive the smallest share of the training pie."
Women are stronger supporters of the right to request training - 75% compared to 67% of men.
Unskilled denied training
Staff who do not have formal qualifications are offered the fewest training opportunities by their bosses, according to a report by YouGov and the TUC.
