Sacred Heart Congregation was incorporated on April 4, 1917, with the permission of Archbishop Sebastian Messmer of Milwaukee. The parish, founded as a Roman Catholic Croatian community, welcomed its first pastor, Fr. Placid Belavic, a Croatian Franciscan friar-priest. The parish purchased its first church in 1917 from Lutherans at 7th and Galena, a church built in 1870. During its early years, the parish experienced significant growth and change as it sought to define its identity.

In 1922, Fr. Dragutin Jesih took over as pastor, working tirelessly to make the parish a thriving center of both religious and social life for the Croatian people in Milwaukee. During his tenure, Sacred Heart Parish saw the formation of several organizations, including the Croatian Catholic Union, the Young Ladies Sodality, the Croatian Eagles Soccer Club, the Altar Society, and the Holy Name Society. After Fr. Jesih's departure in 1930, the Croatian Franciscan Friars continued to serve the parish for over 90 years.

After enduring the Great Depression and World War II, the parish moved to its current location at 49th and Wells. The first Mass at this new site was celebrated in November 1949. By 1956, the parish hall and kitchen were completed, followed by the opening of Sacred Heart Elementary School in 1957, with the Daughters of Divine Charity from Akron, Ohio, overseeing its operation. The parish continued to grow spiritually and materially, developing into a vibrant community with a church, school, rectory, and convent.

In the 1960s, the parish welcomed a growing number of English-speaking Catholics from diverse backgrounds. The parish embraced its expanding community, encouraging active participation in church and school activities. Following the Second Vatican Council (1962-1965), Sacred Heart implemented changes such as celebrating Mass in both Croatian and English, fostering greater participation from the laity in the liturgy.

The Bell Tower, Grotto, & other milestones

In 1979, the parish built the bell tower that stands in front of the church, featuring the original bells donated by parishioners in 1917. The bells' first ringing moved many to tears, as it marked the return of a cherished sound that had been silent for 30 years. Beneath the bell tower is a grotto dedicated to the Blessed Mother, which remains a beloved gathering spot for parishioners.

The 1990s were marked by significant milestones, including the Republic of Croatia's statehood in 1991, supported by the parish’s spiritual and material contributions. In 1993, after 36 years of service, Sacred Heart Elementary School graduated its final class, concluding an important chapter in the parish’s history.

Throughout its history, Sacred Heart Parish has remained a welcoming and diverse community, open to all who wish to visit, pray, learn, worship, and serve. The parish continues to embody the values of faith, unity, and service, striving to live out the Gospel of Jesus Christ. With gratitude for past blessings and trust in God’s continued guidance, Sacred Heart looks forward to its future, united in its mission to proclaim and celebrate the Sacraments and to serve one another in love and faith.