A Queen's Award for Voluntary Service recognises the contribution of Northwood and Pinner Liberal Synagogue's Bereavement Support Group over a 17-year period.
The group has provided comfort and support to those within and outside the Jewish community who have suffered a bereavement.
At Sunday's ceremony, local MP Nick Hurd - also Minister for Civil Society, whose department administers the Queen's Award - said it was the volunteers' Oscar.
Accepting the award, group leader Richard Conradi said that "much of the work is its own reward. Being able to make even a small difference to people at the most difficult moments in their lives - that's what our community is all about."