The offer is available to new and existing customers and can be opened as an individual or a joint account.
The minimum investment is £1 and the maximum £250,000.
Marcus now has two savings products - an easy access Online Savings Account at a rate of 1.3% AER variable and the new 1 Year Fixed Rate Saver.
Marcus managing director Des McDaid, said: “We are committed to offering customers different products to suit different needs and savings goals, particularly during this time of uncertainty.
“The launch of our 1 Year Fixed Rate Saver provides our customers with more options to manage their finances by allowing them to lock in their rate for a 12-month term.”
Marcus savings accounts are managed online however telephone support is available from a UK-based Customer Care Team on weekdays (excluding bank holidays) from 8am to 8pm.
Marcus has been operating in the US since 2016, with the UK launch in 2018 its first international expansion.
• The Bank of England confirmed yesterday the base rate would remain at 0.1%.