Melanie Harris, 44, emptied the bank account of 65-year-old Ted Carter, who had cerebral palsy, and used it for shopping trips and family presents.
Harris, from Barnstaple, had denied one count of fraud but was jailed for two-and-a-half years for the thefts which took place between 2011 and 2013.
The Recorder said she had abused "a highly vulnerable housebound man".
Harris was responsible for looking after Mr Carter and his wife who used a wheelchair, at their bungalow in Wikley Close, Barnstaple, as a team leader with the private care provider, Cygnet Care.
Police described her house in Fremington as "looking like a show home", after Harris used the couple's debit card on a series of shopping trips, Exeter Crown Court heard last year.
Harris, who hid Mr Carter's bank statements to cover up the thefts, was caught after another carer noticed Mr Carter's money had been used for a baby shower.
Recorder Philip Mott said: "He trusted you with his card, PIN and passbook and trusted you as a co-signatory. As a result, you had complete control over his accounts."
The recorder said Harris was motivated by "family expenses", and cited the probation report which spoke of her "greed and a desire to fund a lavish lifestyle".

Gary Nixon, 44, fled to Scotland after advertising tickets online for the Sweden v England match in Germany and said he could arrange accommodation.
But two victims from Ogmore Vale, Bridgend county, received nothing.
Nixon, of Dundee, admitted obtaining property by deception at Bridgend magistrates.
Nia James, prosecuting, said: "He left his home address in the south Wales area after realising he was in trouble and couldn't refund the money."
The court heard Nixon was forced to "beg and borrow" under false names when he lived in Fintry, Dundee.
Magistrates were also told he "had lost everyone and everything over this passage of time" all because of his World Cup con but was now in full-time employment in England and was keen to pay his victims back.
A third victim could not be traced.
Magistrates ordered him to pay his victims back the sums of £590 and £220 and he must do 80 hours unpaid work.

Sir Paul is worth an estimated £20m more than last year and enjoys a significant boost from his American heiress wife's £150m stake in her family's US trucking business.
It puts him well ahead of his nearest rival on the list, Andrew Lloyd Webber, who is estimated to be worth £650m.
The full list will be published by the newspaper on 26 April.
Of the 1,000 richest people in the UK and the 250 wealthiest in Ireland, the list puts Irish band U2 at third place with £431m.
Pop veteran Sir Elton John and Rolling Stones' frontman Sir Mick Jagger follow with their fortunes, thought to be worth £270m and £225m respectively.
1. Sir Paul McCartney and Nancy Shevell £730m
2. Lord Lloyd-Webber £650m
3. U2 £431m
4. Sir Elton John £270m
5. Sir Mick Jagger £225m
6. Keith Richards £210m
7. Michael Flatley £195m
=8. Ringo Starr £180m
=8. Sting £180m
9. Roger Waters £160m
For the third year running, singer-songwriter Adele, who is 26, has topped the list for young music millionaires under the age of 30 in Britain and Ireland, with an estimated fortune of £50m.
The four members of the boy band One Direction plus former band mate Zayn Malik share the second spot with an estimated wealth of £25m each.
One of the fastest rising new young stars is the 22-year-old soul singer Sam Smith, who is currently in the running for the prize for the most played song of the past year at The Ivor Novello songwriting awards.
The Stay With Me singer has amassed a personal fortune of £12m since rising to fame in late 2012.
A care worker has been jailed for stealing £75,000 from a patient to spend on a "lavish lifestyle".
[NEXT_CONCEPT]
A conman who went on the run for nine years after staging a £900 scam selling England tickets for the 2006 football World Cup, has handed himself in.
[NEXT_CONCEPT]
Former Beatle Sir Paul McCartney has topped the Sunday Times Rich List of musicians with his £730m fortune.