Borussia Dortmund and Hertha Berlin players took a knee together around the centre circle before their meeting at Signal Iduna Park.
Dortmund players warmed up in T-shirts with messages including "no peace, no justice" and "united together".
Bayern Munich players wore T-shirts which said "red against racism" before their 4-2 win at Bayer Leverkusen.
The Bundesliga leaders also wore armbands which read "Black Lives Matter" during the game.
Mainz's Cameroonian striker Pierre Kunde took a knee after scoring his side's second goal in their 2-0 win at Eintracht Frankfurt.
This week, sports stars including Serena Williams, Paul Pogba and Lewis Hamilton have raised their voices over police brutality against black people in America.
Huge anti-racism protests have taken place after George Floyd, an unarmed black man in handcuffs, died after a white policeman knelt on his neck for nearly nine minutes.