LGBT+ rights campaigner Peter Tatchell claimed the force had in the past been one of the most homophobic in Britain and had led a "vicious witch hunt" against gay people.
But his call for Craig Guildford to apologise for the "often illegal and abusive way that anti-gay legislation" was enforced has been rejected.
In a letter to Mr Tatchell, Mr Guildford, who led the WMP march at Birmingham Pride last week, said: "I politely decline your invitation to make a formal apology.
"The role of the police is to apply the laws made by politicians who you and I elect as citizens of this country without fear or favour. I remain positively optimistic for the future."
Mr Guildford said West Midlands Police (WMP) had historically enforced laws that "we all would view very differently today".
He said his force's attendance at Pride "illuminates a clear message that I, and WMP, stand side by side with the LGBT+ community, and will continue to do so without fear or favour."
He added that WMP was making progress to support LGBT+ communities but acknowledged there was still work to do "to ensure everyone within the West Midlands, and indeed this country feels safe and happy to be who they are, to love who they truly love, and to be their whole self both in the workplace and in public without judgement or fear."
Mr Tatchell said in response: "The Chief Constable is being disingenuous. We did not ask the police to say sorry for enforcing the law. Our request was for an apology for the often illegal and abusive way they enforced anti-gay legislation.
"In the past, his force went way beyond merely applying the law. It waged an unjustifiable vicious witch-hunt against the LGBT+ community.
"The excessive, over-zealous, homophobic and downright nasty way the police enforced the law wrecked the lives of thousands of LGBT+ people over the decades.
"The West Midlands force was one of the most homophobic in Britain. It went out of its way to target consenting, victimless behaviour that harmed no one in a shameful, cynical bid to boost its arrest and conviction rates."
He has called for a formal apology to "draw a line under past homophobic persecution and help improve LGBT+ trust and confidence in the police to report hate crime, domestic abuse and sexual assault".