Janet W. O'Brien

{{Short description|Massachusetts politician}}

{{Use mdy dates|date=May 2025}}

{{one source|date=January 2022}}

{{Infobox officeholder

| honorific_prefix =

| name = Janet W. O'Brien

| honorific_suffix =

| image = 1995 Janet OBrien Massachusetts House of Representatives.png

| alt =

| state_house = Massachusetts

| district = 5th Plymouth

| term_start = 1991

| term_end = 1999

| predecessor =

| successor =

| prior_term =

| alma_mater = Tufts University (BA)
Harvard University (MPA){{cite web | url=https://archive.org/stream/publicofficersof19931994bost/publicofficersof19931994bost_djvu.txt | title=Public officers of the Commonwealth of Massachusetts }}

}}

Janet W. O'Brien is an American Democratic politician from Hanover, Massachusetts. She represented the 5th Plymouth district in the Massachusetts House of Representatives from 1991 to 1999.