People with underlying health conditions, those who are pregnant and those over 65 will all be offered the vaccination.
More than 550,000 children aged between two and 11 will be offered the nasal spray vaccination following the extension of the flu vaccination programme in 2014.
Children aged five to 11 will be vaccinated at school, while those aged two to five will be offered the vaccination at their GP practice.
Parents of pre-school children will be contacted and encouraged to make an appointment with their doctor to increase overall uptake.
Healthcare workers will also be urged to get the vaccine.
Public health minister Maureen Watt said: “As the national flu immunisation programme gets under way, I want to encourage all those who are eligible to join with us in being ready for flu.
“I will be getting the vaccine this year, as I have every year, as I have asthma and know that getting flu could have a serious impact on my health. I’d rather make sure I’m covered and not have to worry about the consequences.
“The flu vaccine offers the best defence against the most common strains of the virus circulating this year and has an excellent safety record.”
Ms Watt added: “It takes ten to 14 days to work, so I urge eligible groups to make an appointment with your GP practice today.”
Dr Nicola Steedman, Scotland’s acting Deputy Chief Medical Officer, said: “Even if you or your child were immunised against flu last year, it is important to receive the vaccine again this year, as the viruses can change over time.”