Tomari Station is served by the Ainokaze Toyama Railway Line and is 95.4 kilometres from the starting point of the line at Kurikara.

Many through services from the neighbouring Echigo Tokimeki Railway Nihonkai Hisui Line terminate at Tomari, with both Echigo Tokimeki Railway trains and Ainokaze Toyama Railway trains using Platform 2 to provide a same-platform transfer.

[2] With the privatization of Japanese National Railways (JNR) on 1 April 1987, the station came under the control of JR West.

[2] From 14 March 2015, with the opening of the Hokuriku Shinkansen extension from Nagano to Kanazawa, local passenger operations over sections of the Hokuriku Main Line running roughly parallel to the new shinkansen line were reassigned to different third-sector railway operating companies.

[1] From this date, Tomari Station was transferred to the ownership of the Ainokaze Toyama Railway.