Borgomezzavalle is a comune situated in the Valle Antrona, Province of Verbano-Cusio-Ossola in the Italian region Piedmont. In 2019 the population was 320 and as of 2023 it was 290. Its patron saint is St Mary, whose feast is held on the 8th September.

It was established on 1 January 2016 by the merger of the municipalities of Seppiana and Viganella.

The coat of arms and the banner of the municipality of Borgomezzavalle were granted by decree of the President of the Republic of 15 March 2018.

Coat of arms quartered: in the first, a sky blue field, a trapezoidal iron mallet sable, placed dexter, with a long handle gules, placed in band, the end of the handle crossing a water wheel argent, placed sinister, the handle supported centrally by a stone fulcrum gules, this resting on a mass of water azure, billowing argent, in the manner of a plain, the water wheel partly submerged in the water; in the second, vert, a lily or, accompanied by two diminished bands, one at the head, the other at the tip, of the same; in the third, vert, a chestnut vert, fruited with sevens or, stemmed and rooted in the natural way; on the quarter, or, a natural vine, uprooted therefrom, two leaves of vert, the horizontal shoots joined to four bunches of grapes, set in a pale, purple, two to the right, two to the left. External ornaments of the Municipality.

The new emblem incorporates the same elements present in the coats of arms of the municipalities of Seppiana and Viganella.