Jackie and John Fletcher from Warrington, Cheshire, received the money to help care for their son Robert, now 18, who has frequent epileptic fits, is unable to talk, stand unaided or feed himself.
A medical assessment panel granted the award after concluding Robert was left severely disabled by the MMR vaccine.
The family successfully appealed after their application for compensation under the Government's Vaccine Damage Payment Scheme was originally denied in 1997.
Polly Tommey, who believes her son Billy was left autistic after having the combined measles, mumps and rubella jab, said she hopes it will mean more cases will be looked at where other parents suspect their child has been affected by MMR.
Mrs Tommey, from Hampton, Middlesex, labelled the ruling a "milestone".
The mother-of-four, who edits the magazine The Autism File, said: "This is a huge step forward. It is the first time in this country it's been acknowledged that the MMR vaccine is not 100% safe.
"If parents say the vaccine is not safe, there should be proper independent research carried out.
"MMR and autism was a completely taboo subject in the past - not now because of what has happened."
The Department for Work and Pensions, which administers the payment scheme, said it did not hold information on the number of payouts made relating to MMR or other vaccines.
A spokesman said: "When a case is being assessed, it is not a requirement for the medical adviser to state which vaccine the damage has been attributed to, nor is it a requirement to list the disability condition that gives rise to the award."
Mrs Fletcher, who runs the pressure group JABS, Justice Awareness and Basic Support, told The Mail on Sunday: "My husband and I have battled 18 years for the cause of Robert's disability to be officially recognised."
A Department of Health spokesperson said: "This decision reflects the opinion of a tribunal on the specific facts of the case and they were clear that it should not be seen as a precedent for any other case.
"The safety of MMR has been endorsed through numerous studies in many countries. Thankfully, more parents are having their children vaccinated with MMR and consider it as safe as other childhood vaccines.
"MMR vaccine has been used extensively and safely around the world for over 30 years. Over 500 million doses have been given in over 100 countries.
"The World Health Organisation recognises MMR as being a 'highly effective vaccine which has an outstanding safety record'.
"Parents and carers should continue to get their children immunised when called to do so."