The traditions of the St. Denis parish began 154 years ago, founded by a young Irish immigrant named Dennis Martin. His was one of the first wagon trains across the Sierras. A laborer in the lumber industry, Martin became a wealthy man shipping lumber to San Francisco. A dedicated Catholic, Martin wanted to build a church for there wasn't one between Santa Clara and San Francisco. So it became the first church of its kind in San Mateo County serving about 50 families from the surrounding areas. The old church was eventually torn down and the cemetery neglected. Stanford acquired the land and put up a plaque along with the San Mateo Historical Foundation and Church of The Nativity to honor the church and named it St. Denis. St. Denis is a Christian martyr and saint that was Bishop of Paris and martyred in 250 A.D.
The new St. Denis Parish was established 49 years ago and the current site was dedicated in 1963. The church continues to have an important role in its surrounding community, continuing on the tradition of its founder Dennis Martin. In 1995, there was a merger between St. Denis Parish and Our Lady of the Wayside Parish. In the late 90s their growth inspired them to expand their religious education facilities and raised about one million dollars to build a multi-use Parish Center.