Knights of Columbus Marian Council 3840, located in Cedar Lake, Indiana, is currently led by Grand Knight Tom Bachan. Council was founded in April of 1954, and has members from several local churches including Holy Name (Cedar Lake).

The Marian Council 3840 banquet hall is located just North of 133rd on Wicker Ave. (US Hwy 41) in Cedar Lake. Council meetings commence on the second Thursday of every month.

Council activities include the annual Tootsie-Roll drive benefitting mentally disabled children, Blood Drives, Pro-Life activities, Walk for Life, and many other endeavors to benefit the Cedar Lake community.