Smash Mouth’s lead singer Steve Harwell has been cremated following his death earlier this month … and we’re told the late artist’s memorial will be open for all fans to attend.

Steve’s manager, Robert Hayes, tells TMZ … the ashes will be buried at Los Gatos Memorial Park in San Jose, CA — and his loved ones want Steve to have a headstone marker they can continue to visit and leave flowers at.

We’re told he was supposed to be laid to rest next to his mother in San Jose’s Oak Hill Memorial Park, but, unfortunately, there was no space available close to her … so they opted for Los Gatos instead.

Steve’s memorial will be open to the public on October 7 at Los Gatos — over 300 folks have already confirmed they’ll be attending, including his Smash Mouth bandmates. A private reception for family and close friends will follow.

TMZ broke the story, Steve passed away on September 4 due to liver failure — he was surrounded by friends and family at his home in Boise.

The group’s longtime frontman was in hospice care when doctors told him he only had a few days to live.