"My ideal Sunday is a day of reflection and rest - everybody deserves that!" Mr Corbyn said.
The government wants to let local authorities decide how long large stores should be able to open on Sundays.
Currently shops over 280 square metres in England and Wales are only allowed to open for six continuous hours.
Many Christians have opposed the change and the Church of England has joined with shop workers unions in the Keep Sundays Special campaign against it.
Mr Corbyn has now signalled his support for the movement.
A recent survey of over 10,000 workers found 91% were against a change in the law.
I'm backing the @ChrLeft campaign to keep #oursunday pic.twitter.com/WGejhnC6PY
— Jonathan Reynolds MP (@jreynoldsMP) September 28, 2015Usdaw General Secretary John Hannett said: "Our members in large stores remain absolutely opposed to extended Sunday trading.
"The number one reason for their opposition is the detrimental effect this would have on their family life.
"They also cited real concerns about the additional pressure they would come under to work on Sundays if shops are open longer."
In August the government wrote to Church of England bishops asking them not to reject the proposals but the Church continues to campaign against them.
Great to see @stephenctimms supporting the #oursunday campaign at #lab15 http://t.co/kI7ufS4yOa pic.twitter.com/2cokjgDt9S
— ChristiansontheLeft (@ChrLeft) September 27, 2015