Its first issue was published December 8, 1870, by W. A. Greenough & Co., known for publishing directories. During the next few years the paper changed ownership several times, early owners including Russell Conwell, then a Somerville resident, and John A. Cummings, later mayor of the city. On October 20, 1876, the paper came into the control of the Somerville Journal Company, under the presidency of J. O. Hayden. Hayden later became president of two Somerville banks, and treasurer of Middlesex County. With the change of ownership, the paper, which had previously been printed in Boston, began to be printed in Somerville, first in an office on the third floor of the Hill Building in Union Square, then, in July 1894, in the Somerville Journal Building, built for that purpose. Other magazines printed in the Somerville Journal Building included the Journal of Education, the American Primary Teacher, and The Writer. A founder of The Writer, William Henry Hills, bought an interest in the Somerville Journal Company in 1890, and was reported as editor of the Journal and president of the Company in 1895.
The "Pencilings" column of the Journal became popular, with excerpts appearing in newspapers nationwide. It was started by George Russell Jackson, an editor of the Journal, continued for a year by C. H. Hoyt, and then, from January 1885, by Hills.
A rival newspaper, the Somerville Citizen was started in 1888, first in the Stickney Building on Pearl Street, and later moved to Gilman Square. It was united with the Somerville Journal in 1901.
The Somerville Journal's official web site is called "Wicked Local Somerville", where it is part of "Wicked Local", the GateHouse Media New England newspaper site, formerly the Community Newspaper Company.
The current editor, since June 25, 2009, is Debra Filcman, formerly editor of the Needham Times. She replaced Kathleen Powers, who was editor from 2000 to 2009.  George Donnelly was editor from 1987 to 1991.