Miami announced earlier this month that they had agreed to mutually part ways with Diego Alonso, the Uruguayan coach who oversaw their inaugural season.
The club finished 10th in the Eastern Conference on their MLS debut, making it to the playoffs play-in round, where they were beaten 3-0 by Nashville.
Now Neville, who left his role as head coach of England’s women’s national team with immediate effect earlier on Monday, will take his first leading job in the men’s game.
The 43-year-old was appointed manager of the Lionesses in January 2018, guiding them to the semi-finals of the 2019 Women’s World Cup.
However, he was set to leave the job this summer upon the expiry of his contract, with Sarina Wiegman, currently in charge of the Netherlands, to take over after the Olympic Games.
Beckham, the president and co-owner of Inter Miami, spent nine years playing in the Man Utd first team with Neville, the pair winning 12 major trophies together – including six Premier League titles and the Champions League.
They also played together for England, both making their senior international debuts in 1996.
“I am incredibly delighted for this opportunity to coach Inter Miami and to work with Chris and the entire ownership group,” Neville said of the appointment.
“This is a very young club with a lot of promise and upside, and I am committed to challenging myself, my players and everyone around me to grow and build a competitive soccer culture we can all be proud of.
“This fantastic soccer-loving market deserves consistent performances and a winning mentality, and I look forward to getting to work.”
Inter Miami co-owner Beckham added:
“I am very happy with the leadership group we have established to lead the team as we turn the page following our inaugural season and look forward to having Chris and Phil join us soon.
“I have known Phil since we were both teenagers at the Manchester United Academy. We share a footballing DNA having been trained by some of the best leaders in the game, and it’s those values that I have always wanted running through our club.
“Phil has deep experience in football, as a player and as a coach at both club and international level, and over his career he has worked with many of the finest managers and players in the game.
“I know his qualities as a person, his decency, loyalty and honesty – and his incredible energy and work ethic. Anyone who has played or worked with Phil knows he is a natural leader, and I believe now is the right time for him to join.”