Will Ferrell

Sherlock Holmes

John C. Reilly

Dr. John Watson

Rebecca Hall

Dr. Grace Hart

Kelly Macdonald

Mrs. Martha Hudson

Rob Brydon

Inspector Lestrade

Lauren Lapkus

Millie

Pam Ferris

Queen Victoria

Ralph Fiennes

Prof. James Moriarty / Jacob Musgrave

Adam Scherr

Brawn

Kieran O'Brien

PC Smalls

Noah Jupe

Doxy

Bella Ramsey

Flotsam

Colby Mulgrew

Haybag

Scarlet Grace

Pickle

Billy Jenkins

Mud Fog

Michael Culkin

The Judge

Jana Pérez

Lestrade's Wife

Wolf Roth

Sigmund Freud

Nathan Osgood

Mark Twain

David Shackleton

Albert Einstein

Paul Cassidy

Charlie Chaplin

Ben Lee

Houdini

Bronson Webb

Jonathan Nightingale

Jamie-Rose Monk

Mrs. Nightingale

Billy Zane

Billy Zane

Jason Thorpe

Butler

Robert Cawsey

Waiter

Stanley Eldridge

Waiter

Oliver Maltman

Telegraph Operator

David Stoller

Hudson's Guard

Jack Riley

Newschild

Lilly Aspell

Newschild

Ethan Rouse

Newschild

Ellie Rose Eames

Newschild

Jamie Baughan

Titanic Ship Officer Liaison

Helen Duff

Titanic Guest

Jess Liaudin

Hangman

Wesley Kent-Hargreaves

Weird Child Companion

Daniel Fearn

Drooling Man Companion

Darren Lake

Disorientated Man Companion

Martin Bishop

Priest

Gerard Monaco

Titanic Ship Officer

Michael Buffer

Fight Fan #1

Bruce Buffer

Fight Fan #2

Russell Wilcox

Announcer

Hector Bateman-Harden

Young Sherlock Holmes

Codie-Lei Eastick

Young Watson

Laura Stevely

Sherlock's Mother

Layla Rose Boyce

Nicotine Stains / Nancy

Sadie Newman

Jane

Harry Baxendale

Seamus

Ella Bright

Bridgette

Kenneth Hadley

Headmaster

Paul Bigley

Teacher #1

Sue Maund

Teacher #2

Tommy Gene Surridge

Inky Hands

Paddy Holland

Tough Kid

Hugh Laurie

Mycroft Holmes (uncredited)

Steve Coogan

Gustav Klinger (uncredited)

Phil Hodges

Mr. Algernon Barkworth (uncredited)

Sara Beasley

Mrs. Frobisher (uncredited)

James Eeles

Manager Mr. Petrucka (uncredited)

Paul T.T. Easter

John (uncredited)

Jordan Long

Herbert (uncredited)

Sonnyboy Skelton

Doxy's Dad (uncredited)

Willem Dalby

Newsie Man (uncredited)

Riley White

Newsie Kid - Jimmy (uncredited)

Lochlan White

Newsie Kid - Timmy (uncredited)

John Kinory

Instructing Solicitor (uncredited)

Benjamin Lok

Courtroom Person 3 (uncredited)

Joseph Macnab

Fitness Instructor (uncredited)

Martin Bassindale

One Man Band (uncredited)

Amelia O'Loughlin

White Star-Line Girl (uncredited)

Matthew Di Liello

Telly-Phone Assistant (uncredited)

Craig Thomas Lambert

Yeoman of the Guard (uncredited)

Jorge Leon

British Soldier (uncredited)

Martyn Mayger

Buckingham Palace Guest (uncredited)

Hugh O'Brien

Garden Party Guest (uncredited)

Deepak Anand

Nobleman (uncredited)

Shawn Dixon

Upper Class Gentleman #1 (uncredited)

Anthony Richard Rowe

Victorian Gentleman (uncredited)

Mick Slaney

Docker (uncredited)

Karl Farrer

Russian Merchant (uncredited)