You can specify distinct for one or more attributes using Sequelize.fn
Project.findAll({
attributes: [
// specify an array where the first element is the SQL function and the second is the alias
[Sequelize.fn('DISTINCT', Sequelize.col('country')) ,'country'],
// specify any additional columns, e.g. country_code
// 'country_code'
]
}).then(function(country) { })