PC Dixon, known as "Dixie" to friends, was based at Loddon Valley police station, near Reading.
AN on-duty police officer and a 91-year-old woman have died after a collision on the A4 Bath Road, near Wargrave.
She said: "I'm sure the whole house will wish to join me in offering condolences to the family, friends and colleagues of police constable James Dixon from Thames Valley Police who was killed while on motorcycle duty yesterday".
"In policing we often talk about the strength and importance of the police family and that is never more so as we share in the pain of loss and offer support to one another at this time of need". "We know this is a hard time of the year for anyone with Christmas coming but we are hoping to raise some funds to support the family of James Dixon".
He added that all the force flags would be flying at half-mast for the next week as a mark of respect.
Tributes were also paid on the social media accounts of police forces across the country, while Stephen Kavanagh, chief constable of Essex Police, tweeted: "Such sad news". "Its well respected officers like PC Dixon that inspire me to be a Police Officer".
"IPCC investigators are attending the scene as part of an independent investigation to determine the circumstances which lead to the collision".