Saints have apologised to 117 workers after they were found to have paid them below the minimum wage.
The club was named by the Government on a list of nearly 180 employers for underpaying staff.
In total, the Super League side failed to pay £5,536.92 to 117 workers.
Saints said all affected staff have now been reimbursed.
A spokesman said: “The club is committed to paying the national minimum wage, and operates a policy of paying a premium over and above the national minimum wage.
“However, a limited number of staff were identified as having been underpaid the national minimum wage. This was unintentional, and the club has unreservedly apologised to affected staff.
“Fortunately these instances of underpayment were isolated in nature, and the club has worked with HMRC to resolve the underpayments.
“All affected staff have been reimbursed. The club has reviewed its payroll systems to ensure that the strict requirements for calculating compliance with the national minimum wage regulations are observed.”
Later this month the Department for Business, Energy and Industrial Strategy will launch a campaign to raise awareness of the new rates and encourage workers to speak to their employer if they think they are being underpaid.
Business Minister Andrew Griffiths said: “The world of work is changing and we have set out our plans to give millions of workers enhanced rights to ensure everyone is paid and treated fairly in the workplace.
“There are no excuses for short-changing workers. This is an absolute red line for this Government and employers who cross it will get caught - not only are they forced to pay back every penny but they are also fined up to 200 per cent of wages owed.
“Today’s naming round serves as a sharp reminder to employers to get their house in order ahead of minimum wage rate rises on 1 April.”