FIRST (For Inspiration and Recognition of Science and Technology) 
National program with local teams in Greater Boston
Cost: $$$
FIRST introduces kids to robotics as a way to promote technological life skills. Programs for children in Kindergarten through grade 12 are separated into four groups, starting on the early level with motorized Lego contraptions and up through self-built robots. Teams compete in seasons, many in local cities and towns around Boston, that culminate in competitions (see photo above). There are no per-student fees, but team fees can cost several thousand dollars each season. FIRST has established a grant program to financially help under-served communities. 

Zaniac
358 Cambridge Road, Woburn, MA 01801 
Cost: $$$
Zaniac offers STEM-based after-school programs for kids in Kindergarten through grade 8, including Lego robotics classes. These hands-on, instructor-led gatherings promote mechanics, robotic design, and environmental science. Groups meet once a week for 90 minutes on various days.

Einstein's Workshop   
25 Adams St., Burlington, MA 01803 
Cost: $$$
Einstein's Workshop offers Lego-themed robotics classes for Kindergartners through eighth graders (classes currently meet on the weekends). And how cool is this? The company has its own home-built, 8-by-8-foot “field” for combative robotic tournaments.

Empow Studios  
1776 Massachusetts Ave., Lexington, MA 02420 
Cost: $$$ 
The Programming and Robotics Club at Empow Studios focuses on application languages and ties in this learning with robotics as a way to bring programming to life. The club meets Sundays for children in grades 2 through 8.

The Maker Mill
4 High St., Suite 128, North Andover, MA 01845
Cost: $$$
The Maker Mill's weekly robotics classes draw kids in with a gladiator-like theme, as students create "battlebots" to eventually enter into a showdown. For children from grades 3 through 8.

Photo Credit: Adriana M. Groisman