https://www.census.gov/newsroom/press-releases/2020/south-west-fastest-growing.html
Among cities with a population of 50,000 or more, Phoenix, Arizona (pop. of 1,680,992) was the fastest growing large city from 2010 to 2019 according to the US government census.
Austin, Texas (population almost 1 million = 978,908) was the fifth fastest growing large US city from 2010 to 2019. The Austin-Round Rock-Georgetown, Texas metropolitan statistical area was the fastest growing US metro area.