Around 1927, Piazza's mother Margaret Luft wed Reuben Davis Breland, whose surname Marguerite adopted.

In 1950, Piazza made her Broadway debut, in Happy as Larry, with Burgess Meredith directing and starring in the title rôle, and Alexander Calder designing.

[6] She performed and was a noted philanthropist in her adopted hometown of Memphis, where she was a longtime supporter of St. Jude Children's Research Hospital.

[8] On January 15, 1973, the Willis Music Company published Marguerite Piazza's Christmas Carol Sing-Along Party.

Piazza was inducted into the Memphis Music Hall of Fame in 2016, becoming the first opera singer to be honored by the organization.

Marguerite Piazza died in Memphis, Tennessee, on August 2, 2012, aged 92, from congestive heart failure, and was survived by her five children and large extended family.