SpringfieldMoms.org posted a great article listing all of this years garage sales. If you have any to add, please comment!

• May 10: Oak Mill Estates in Rochester (newer subdivision under the water tower) is having a Friday night only, rainout/2nd attempt sale
• May 10-11: Indian Hills garage sales. Fri. 10:30-7:00 Sat. 8:30-1:00
• May 10-11 Craft-a-Holic Garage Sales Friday 3pm-8pm and Saturday 8am-3pm. At 1725 Homewood Ave(in Jerome). Area crafters have cleaned out their closets. Scrapbooking, Stamping, Needlework, Jewelry, Floral, Painting and more.
• May 11: Mt. Auburn Community Rummage Sales – 8:00 am
• May 16: Miracle Do Happen Fundraiser Yard Sale for ongoing medical expenses for two children with mitochondrial disease. At Elm Street Christian Church, 3020 East Elm Street, Springfield. Also: games, prizes, bake sale, live music by Dan Wilson.
• May 17-18: Morrisonville town wide garage sale.
• May 17 – 18: New Berlin town wide garage sale.
• May 17-18 Palisades Subdivision in Springfield (off of Hilltop Road) Garage Sales Friday 4-7 and Saturday 8-12
• May 17-18 Deerfield subdivision neighborhood garage sale May 17th 4-8 pm and  May 18th 7-noon
• May 17-18 Twin Lakes annual subdivision garage sales are Saturday May 18th, with a preview Friday evening the 17th.
• May 17-18 Park Forest Place subdivision-wide sale in Rochester off of Oak Hill Rd. Fri 4 – 7, Sat 8 – 12
• May 17-18 Trevi Gardens neighborhood garage sales (near Southwinde Park)
• May 17-18 Lakewind Acres neighborhood garage sales (near Southwind Park)
• May 18Cobblestone Subdivision, Springfield  Head to West Iles @ Meadowbrook and throughout the subdivision.  8:00 am – 3:00 pm.
• May 18: Koke Mill East neighborhood – enter at Koke Mill and Spring Mill Drive in Springfield, 8- noon
• May 18: West Koke Mill subdivision annual garage sale
• May 18: Scarborough Place neighborhood garage sale. Take Iles west to Chicory Drive, turn left. May 18. 8-noon
• May 18: Springfield Senior Center’s Annual Flea Market – rain date: Sunday May 19th) 9:00a.m.-2:00p.m. at 701 W Mason St., Springfield
• May 18: Westchester subdivision garage sale is Saturday 7 – 1
• May 18: Country Club Estates neighborhood garage sale from 8-12.
• May 24-25: Annual Sherwood Subdivision Yard Sales. Sherwood is the large subdivision located off Wabash Avenue, bordered by Chatham Road and Veterans Parkway. Most sales will start at 8 am

• May 31-June 1: Timberlane East Garage Sales

  (Springfield/Rochester) – located on Hill Top RD just south of Route 29. May 31 8 a.m. to 7 p.m and June 1st 8 a.m. to noon.

Source: http://springfieldmoms.org/area-neighborhood-garage-sales/

You can also find garage sales:

http://springfieldil.craigslist.org/gms/
http://www.yardsalesearch.com/garage-sales-springfield-il.html