Actor Character Seasons 1 2 3 4 5 6 7 8 Len Cariou Commissioner (ret.) Henry Reagan Main Tom Selleck Commissioner Francis “Frank” Xavier Reagan Main Donnie Wahlberg Detective Daniel “Danny” Reagan Main Bridget Moynahan ADA Erin Reagan Main Will Estes Officer Jamison “Jamie” Reagan Main Amy Carlson Linda Reagan Recurring Also starring Main Sami Gayle Nicole "Nicky" Reagan-Boyle Recurring Also starring Main Jennifer Esposito Detective Jackie Curatola Also starring Marisa Ramirez Detective Maria Baez Recurring Also starring Vanessa Ray Officer Edit "Eddie" Janko Recurring Also starring