The Australia international will join the Major League Soccer club pending receipt of his P-1 visa and International Transfer Certificate (ITC) The fee and length of contract have not been disclosed.
Cahill will join former Premier League players Thierry Henry and Teemu Tainio in New York, while former Barcelona defender Rafael Marquez also plies his trade at the Red Bull Arena.
They are currently top of the Eastern Conference and the 32-year-old is desperate to help his side claim what would be their first title.
"I am very happy to start a new chapter of my career with the New York Red Bulls," Cahill told the official website. "As we have seen over the past few years, MLS has developed into a very competitive league with many talented players.
"I am impressed with what the Red Bulls are trying to accomplish in MLS and within American soccer and I am looking forward to this new challenge. I will do everything I can to help bring New York its first MLS Cup."