According to figures, couples spend more in the town than anywhere else in the county for February 14, the new study has revealed.
It put Doncaster ahead of Sheffield – with Rotherham and Barnsley lagging behind in 3rd and 4th place respectively.
Spending in Doncaster was a third more than other big population centres in South Yorkshire.
Woman's terror as man jumps into car at Doncaster petrol station in attempted hijacking
Former Doncaster mayor Martin Winter in court after 'dangerously out of control' dog attacks man
GP surgeries to merge and two new practices planned in Doncaster costing more than £9 million
Video: Watch freak moment 10m high whirlwind whips through Doncaster village
Court round-up: The latest convictions from Doncaster Magistrates' Court
The second highest figures were in Sheffield, followed by Rotherham and Barnsley.
Wakefield was the highest spending location in West Yorkshire.
The figures were compiled by Lovehoney - the UK’s biggest sexual wellness brand - from spending stats on couples’ sexy gift buying in the build-up to Valentine’s.
Lovehoney spokesperson, product director Bonny Hall, said: “Couples in Doncaster are the most romantic in South Yorkshire - spending more on each other than anywhere else in the region in the build-up to Valentine’s.
“Couples that play together, stay together.
“The key to sexual happiness is to be bold and adventurous, especially around Valentine’s Day."
The highest spending town nationally was King's Lynn in Norfolk.
Around 80% of Lovehoney’s customers are in settled relationships and it experiences a big uplift in sales in the month before Valentine’s.
The most romantic places in South Yorkshire according to Lovehoney are:
Originating as a Western Christian feast day honoring one or two early saints named Valentinus, Valentine's Day first became associated with romantic love in the 14th century.