Demi Lovato Passes Out Charity Checks to Celebrate Sobriety

Demi Lovato is awesome ... she's celebrating her 5-years of sobriety by driving around L.A. and donating thousands of dollars to various charities ... TMZ has learned.

Demi delivered a $5,000 check Saturday to Kari Whitman, who runs Ace of Hearts animal rescue. She personally took the check to Kari's home and said she wanted to celebrate her sobriety by giving to worthy causes. She also said she was spending the day "giving back," so that was just her first stop.

The singer had not previously been involved in Ace of Hearts, so it looks like she checked on various animal charities in L.A. and then personally executed her plan.

Demi posted Thursday she was 5-years sober and counting, saying, "I'm so proud of myself but I couldn't have done it without my higher power (God), my family, friend and everyone else who supported me."