The Spanish forward join City last season but struggled for game under Pep Guardiola, having only made 19 appearances in the Premier League.
The expected sale of Nolito is a substantial financial loss for City, who signed him from Celta Vigo last summer for £13.8m.
Nolito did grab five goals and three assists in his limited playing time, effectively proving his worth as a solid substitute.
A return to Celta, who he had played for between 2013 and 2016, had been mooted, but he instead joins Sevilla, a side keen on him since the start of the transfer window and can offer UEFA Champions League football.
First it was reported Manchester City would get around €10m, then it dropped to €9m, and now Estadio Deportivo report Sevilla are paying €8m. "It's very hard. Just "tomorrow", "good morning", "good afternoon" and a little more", he had said.
Everyone at City would like to wish Nolito well with his move.
He becomes the Andalusians' fifth summer capture after Ever Banega, Sebastien Corchia, Guido Pizarro and Luis Muriel.