She said it will ensure wages meets the "real cost of living" - and urged more firms to sign up to the scheme.
The Scottish Government's rate is different from the legally binding UK Govt national living wage of £7.20.
The First Minister revealed the new rate on a visit to the Airdrie headquarters of the Bell Group, a UK-wide painting and decorating contractor which is the latest Scottish business to become accredited to the scheme.
The rate, paid to all workers aged over 18 at organisations which are part of the voluntary scheme, is £1.75 an hour more than the statutory living wage for those aged 21-24 and £1.25 an hour more for those aged 25 and older.
She said: "The new living wage of £8.45 will be a welcome pay rise for thousands of Scottish workers and ensures people's basic wage continues to meet the real costs of living.
"Like the Bell Group, 630 employers in Scotland are now accredited living wage employers and I want to see all businesses implement the new living wage rates as soon as possible.
"For business, paying the living wage makes sense - it's an investment in people and all the evidence shows it leads to increased productivity and reduced staff absence and turnover, while sending a strong signal to customers about fairness.
"Yet we also know around 20% of Scotland's workforce earn less than the living wage. With low pay one of the main drivers of in-work poverty, it's vital that employers who can pay the real living wage do so."
Megan Strachan, 21, is one of the Bell Group employees who will receive the increased living wage, and she said the scheme has enabled her to buy a car and be more independent.
Annette Bell, co-founder of the Bell Group said: "The majority of our staff were already paid well above the living wage, however becoming accredited meant that we could renew our commitment to ensure that all our staff have a decent quality of life."
Ms Sturgeon's announcement was one of four made simultaneously across the UK on Monday, with others in London, Cardiff and Manchester.
Living Wage Foundation director Katherine Chapman said: "As we kick off Living Wage Week today, we are celebrating the 600-plus employers in Scotland and nearly 3,000 employers across the UK who lead the way on tackling low pay by paying the real living wage.
"The sheer growth of our movement shows that the living wage is good for people and good for business."