The campaign has been highlighted across two match rounds, from Tuesday 3 December to Monday 9 December.
Here's how Premier League clubs have been showing their support.
As a gay man who had little interest in football growing up, Allen admitted he did not know what to expect ahead of his visit but left London Stadium feeling welcome.
"Wearing a football scarf at West Ham immediately made me feel like I was part of a community, and that's a lovely feeling, particularly if, for whatever reason in your life, you felt like an outsider," Tom told the club's official website.
"To feel like you're part of something is truly magical."
The players had a spectacular backdrop at Amex Stadium as they lined up ahead of Sunday's match between the Seagulls and Wolverhampton Wanderers.
Liverpool captains Jordan Henderson and Sophie Bradley-Auckland proudly displayed the Rainbow Laces armbands that were worn in the Premier League over the last two Matchweeks.
And Tottenham Hotspur Stadium was a stunning sight as it displayed rainbow colours.