The Ireland striker has a base salary this year of $2,917,741, according to figures released Friday by the MLS Players Union. His total compensation is $3,416,243, including a prorated share of his signing bonus and other guaranteed compensation.
The Galaxy's Landon Donovan, the highest-paid American-born player, was fifth at $2.3 million.
Keane is the 10th-leading goal-scorer in Premier League history, but he played sparingly over the past two seasons. He became interested in MLS when Beckham trained with Tottenham several months ago. He scored in his debut game with Los Angeles last month.
Among other new MLS players, Dutch striker Danny Koevermans, who plays for Toronto, has a $999,996 salary and $1,413,319 in compensation, and his teammate, German midfielder Torsten Frings, has a $699,996 salary and $1,113,663 in compensation.
Midfielder Freddy Adu has a $475,884 salary and $594,884 in compensation with the Philadelphia Union; and German goalkeeper Frank Rost is at $545,460 with the Red Bulls.