Crystal Lake South High School

A girl waves during the graduation ceremony.

A graduate holds up his cap and diploma to the crowd.

Graduates toss hundreds of caps into the air.

A graduate watches commencement speeches.

Two graduates hug following the commencement ceremony.

A graduate waves to the crowd walking into the stadium.

Two graduates pose for a photo following the commencement ceremony.

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A group of female student posing at the color toss event.

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Latest News

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Michelle Kidd holding Inaugural Memorial Award

May 11, 2026

Michelle Kidd Honored with Inaugural Chamber Award

Crystal Lake South teacher Michelle Kidd was honored by the Crystal Lake Chamber of Commerce with the Inaugural Robert & Rosemary Blazier Memorial Award on May 7.

Students holding award from culinary challenge

April 21, 2026

CLS Pair Places Second at MCC Culinary Challenge

Cullen Perri and Temire Onome-Ojigbo place second at McHenry County College High School Culinary Challenge, making four identical dishes in 90 minutes.

Students holding trophy from competition

April 20, 2026

CLS Math Team Students Earn Highest Finish in Program History

The CLS math team had 14 students represent the school at the state finals with two seniors finishing second in the oral competition

March 25, 2026

CLS ACES Team Places Third at State Finals

The CLS ACES team finished in third place at the ACES state competition, their best since 2001

February 23, 2026

D155’s Dr. Lesinski Named Superintendent of Distinction

Dr. Neil Lesinski, superintendent of Community High School District 155, has been named the 2026 Superintendent of Distinction by the Kishwaukee Region of the Illinois Association of School Adminis...

November 20, 2025

D155 Board Approves New CLS Principal for Next School Year

District 155’s Board of Education approved Dan DeBruycker as the next principal of Crystal Lake South High School.

Graphic honoring Ben Stoner's accomplishments

September 18, 2025

Ben Stoner Named 2025 Illinois Theatre Association Award of Excellence Winner

Crystal Lake South High School theatre director Ben Stoner has been honored with the Illinois Theatre Association’s 2025 Award of Excellence in the Secondary Education Division.

September 15, 2025

Crystal Lake South’s EasyLife Earns National Gold Recognition

Crystal Lake South's Virtual Enterprises International (VEI) – Entrepreneurship (Dual Credit) class has earned the Gold Circles of Excellence designation for its student-run virtual company.

CLS at a Glance

2024-2025 Annual Report (English)

Informe Anual 2024-2025 (Español)

School Information

93%

Graduation Rate

#1

District in McHenry County

225+

Courses Offered

37

Dual Credit Offerings

$1.8

Scholarships Earned by Class of 2026

#1

Best Teachers in McHenry County

81%

Teachers w/ Master's Degree or Higher

200+

Sports & Extracurricular Activities Offered

Crystal Lake South High School

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SCHOOL SCHEDULES

ENROLLMENT

PARENTSQUARE

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Upcoming Events

Latest News

Michelle Kidd Honored with Inaugural Chamber Award

CLS Pair Places Second at MCC Culinary Challenge

CLS Math Team Students Earn Highest Finish in Program History

CLS ACES Team Places Third at State Finals

D155’s Dr. Lesinski Named Superintendent of Distinction

D155 Board Approves New CLS Principal for Next School Year

Ben Stoner Named 2025 Illinois Theatre Association Award of Excellence Winner

Crystal Lake South’s EasyLife Earns National Gold Recognition

93%

#1

225+

37

$1.8

#1

81%

200+

Homepage

CALENDAR

SCHOOL SCHEDULES

ENROLLMENT

PARENTSQUARE

SKYWARD

Upcoming Events

Latest News

Michelle Kidd Honored with Inaugural Chamber Award

CLS Pair Places Second at MCC Culinary Challenge

CLS Math Team Students Earn Highest Finish in Program History

CLS ACES Team Places Third at State Finals

D155’s Dr. Lesinski Named Superintendent of Distinction

D155 Board Approves New CLS Principal for Next School Year

Ben Stoner Named 2025 Illinois Theatre Association Award of Excellence Winner

Crystal Lake South’s EasyLife Earns National Gold Recognition

93%

#1

225+

37

$1.8

#1

81%

200+