No!
They are both English but no, they are not related.
no
No
Colin Firth is a British actor who has been in more than 50 movies. He won an Academy Award in 2011 for Best Actor in a Leading Role for his performance as King George VI in The King's Speech.
Colin Firth Heads to Hollywood For His Latest Speech
Colin Firth Arrives Back in London After the Oscars
Colin Firth Wins Best Actor
Colin Firth's Career at a Glance