The Gunners sit top of the table after winning their first five games on the spin, marking their best ever start to a Premier League season, before being beaten by Manchester United.
It is the third time Arteta has won the Manager of the Month award, picking it up earlier this year in March and last September.
Erling has been named Player of the Month for August after scoring a remarkable nine goals in five games in a brilliant start to his career in England.
The 22-year-old bagged a brace on his league debut against West Ham and scored once at Newcastle United before hitting consecutive hat-tricks against Crystal Palace and Nottingham Forest as City won four of their opening five games.
According to Opta, only former Liverpool striker Luis Suarez has scored more goals in a single month in the Premier League, with 10 goals in December 2013.
“I am delighted to win this award for the first time, it was an incredible start of the season for the team and I am grateful to everyone who voted,” Haaland said in a statement.
“We all wanted to hit the ground running this season, so winning four games out of five was a great start for us in what is the most challenging competition in the world. I am happy to have played my part by scoring goals.
“Hopefully, I can continue to support the team … and carry on our strong start to the season.”
