Brown, 29, rushed for 4,815 yards and 36 touchdowns and caught 184 passes for 1,491 yards in Miami. He ran for 1,000 yards in 2006 and made his only Pro Bowl team in 2008.
"Ronnie is an all-around running back with a versatile skill set," Eagles general manager Howie Roseman said in a statement released by the team. "He can run the ball, catch it, and does very well in pass protection. He'll add some good size to our backfield, and he's a good character guy. We think he'll be a tremendous compliment to LeSean (McCoy) and the other young backs on this team that we really like. You can never have enough good running backs in this league, and we are happy to have Ronnie join us."
Before adding Brown, the Eagles' only experienced running backs were starter McCoy, who ran for 1,080 yards and caught 70 passes last season, and Eldra Buckley, who has just 36 carries in two years with the team.
Later in the day, the Eagles signed free-agent offensive tackle Harris to a one-year deal.
Harris spent his first four seasons with the Denver Broncos, starting 34 games. He was their third-round pick in 2007 out of Notre Dame, where he played with Eagles defensive linemen Victor Abimiari and Trevor Laws.
Right tackle is a question mark for the Eagles, with Winston Justice, the starter the past two years, beginning training camp on the injured list with a knee injury. The team has been using second-year pro Austin Howard and former seventh-round draft pick King Dunlap at right tackle during the early days of camp.
Harris started 16 games in 2008, eight in 2009 and 10 last season.
"I appreciate everything the Broncos have done for me," Harris told the Denver Post. "I'm grateful they drafted me, and I built a lot of great relationships with a lot of great people over the past four years. It wasn't an easy decision. But in the end, money had nothing to do with my decision. This was about what I thought was the best opportunity at this point in my career."
Finally, the Eagles scooped up former New England Patriots safety Page late Tuesday. Page, 26, had 12 tackles and two interceptions in 10 games last year for New England. Before that he spent four years with the Chiefs, starting 39 games.
Like all other NFL free agents, Brown, Harris and Page aren't permitted to practice with their new team until Thursday.
In the week before Tuesday's flurry, Philadelphia had already acquired defensive linemen Jason Babin and Cullen Jenkins, cornerbacks Dominique Rodgers-Cromartie and Nnamdi Asomugha, offensive lineman Evan Mathis and quarterback Vince Young.
That plethora of new talent sparked Cowboys defensive coordinator Rob Ryan to call the Eagles the "all-hype team" on Monday, and the additions have made Philadelphia early Super Bowl favorites in the eyes of many.
In other Eagles news Tuesday, the Inquirer reported that wide receiver Jeremy Maclin reported to the team's training camp at Lehigh, Penn. He had been out with an unspecified illness. The team is still waiting for star wide receiver DeSean Jackson to report. Jackson is holding out for more money.
The Associated Press contributed to this report.