Brian Patrick Sullivan (born April 2, 1963) is an American politician who served as mayor of Westfield, Massachusetts from 2016 to 2019.

When incumbent Mayor Daniel Knapik opted to not run for a fourth term in 2015, Sullivan declared his candidacy and defeated challenger Michael L. Roeder in the November municipal election.

[5][6] When Knapik resigned to take a position in Governor Charlie Baker's administration, Sullivan was sworn in as acting mayor and served the remainder of his predecessor's term before beginning his first term on January 4, 2016.

[7][8] He was sworn into office on January 6, 2016, at the Westfield Technical Academy by his father and was succeeded as City Council president by Councilor Brent Bean, II.

City Council President and Ward 2 Councilor Ralph J. Figy was sworn in as Acting Mayor of Westfield on November 12.