Marcus & Millichap is pleased to exclusively represent for sale the Decatur Professional Plaza, a five-story, 36,600 SF GLA, multi-tenant office building located at 363 S Main St in Downtown Decatur, Illinois (ranked the 17th most populous city in the state). Built in 1967, masonry and steel construction, the subject property covers 1.70 acres across two parcels and offers 100 onsite parking spaces, including five ADA-compliant spots. The subject property is zoned B-2 and features a flexible layout ideal for a variety of commercial uses. Recent CapEx improvements include a new roof (2019), chiller replacement (2024), and a well-maintained HVAC system with 15 individual temperature zones. The building features terrazzo flooring, marble wall accents, wood wainscoting on upper floors, two passenger elevators, and ADA-compliant restrooms on the first and third floors. Tenant amenities also include LED parking lot lighting and remodeled common areas. The current tenant mix includes law offices, a travel agency, and salon services, establishing a stable service tenant base. Occupancy is 55.31%, though the building has historically maintained higher levels. Average in-place rent is $11.08 SF, compared to a market average asking rent of $20.17 SF (1.4% annual rent growth per CoStar) providing significant opportunity to mark rents to market in the vacant suites. Located at a signalized corner with ingress/egress from Main Street/Business Route 51, Decatur Street, and Church Street, the subject property lies in the heart of Decatur’s Central Business District. Nearby anchors include the Macon County Courthouse, Decatur Civic Center, and multiple regional and national corporate offices. The city’s economic base is supported by Fortune 500 companies Archer Daniels Midland (ADM) and Caterpillar, as well as Primient, Ameren Illinois, and regional hospital systems (Decatur Memorial and HSHS St. Mary’s). Decatur’s infrastructure includes Route 36, Business Route 51, a regional airport with direct flights to Chicago, and established rail service. The metro draws from a labor force of ~563,000 within a 60-minute drive. The local population is 93,298, daytime population is 97,212, and average household income is $82,125 within 10 miles. The area is served by an educated workforce, supported by Millikin University (Enrollment: 1,800; ranked #1 regional college in Illinois by U.S. News & World Report) and Richland Community College (Enrollment: 2,235). The University of Illinois Urbana-Champaign (Enrollment: 59,238) is located just 50 miles away, further strengthening the region’s talent pool. Decatur Professional Plaza offers a compelling value-add investment opportunity in a historically well-occupied asset with recent CapEx improvements, strong local economic drivers, and substantial upside potential through lease-up and rental rate growth.