A 17-year-old boy was “rugby tackled” outside the Wakefield Estate near Reading during a confrontation with police.
Protestors said they were trying to block a convoy taking Mr Erdogan to a business event.
The teen was being treated for head and back injuries one protestor told the BBC.
Thames Valley Police said in a statement that the protest which turned violent was “facilitated by pro-Kurdish groups”.
It added: “Protesters attempted to block the passage of vehicles and police tactics were deployed to protect the protesters and keep the road clear for the vehicles.”
Mr Erdogan is expected to meet the Queen and Prime Minister Theresa May during the visit, which has sparked a backlash from human rights campaigners and politicians.
The Liberal Democrat leader Sir Vince Cable denounced the Turkish leader as having “an unacceptable disregard for liberal, democratic values.”
He said: “May’s administration appears to have substituted diplomacy for sycophancy in its pursuit of Brexit.
“By permitting a state visit and audience with the Queen, May and Johnson are essentially rolling out the red carpet for a man with a disregard for human rights, who is responsible for alarming oppression and violence.”
The visit has been condemned by critics because of the Turkish government’s oppression of opposition politicians, human rights campaigners and journalists.
Kurdish separatists have been embroiled in a conflict for decades with Turkey as they demand to have their own sovereign state, which overlaps with of Turkey’s territory.
Ahead of the trip, Mr Erdogan said the UK was a “strategic partner and ally” and he hoped to improve important trade relations between the two countries.
He said: “We want to continue our economic relations as the governments of Turkey and the United Kingdom without interruptions after Brexit.”
Erdogan arrived at RAF Brize Norton in Oxfordshire yesterday before travelling to Reading where he told audience members of the Turkish-British Tatlidil forum that both countries were “fighting shoulder to shoulder as responsible nations to defeat terrorism”.
Green Party co-leader Caroline Lucas said she was appalled that the Government was “cosying up” to oppressive leaders.
She said ahead of the state visit: “As we hurtle towards Brexit it’s clear that the Government is increasingly willing to cosy up to repressive leaders from across the world.
“President Erdogan is an autocrat, who inflicts serious harm on his own population – yet we’ve flogged him millions of pounds worth of weapons and now we’re inviting him over for tea.
“It would be utterly appalling if Theresa May doesn’t take this opportunity to stand up to Erdogan’s human rights abuses, and if the only outcome from these meetings was smiling photos with a leader who we’re desperately trying to court before the Brexit crunch begins.”
Mrs May and Mr Erdogan are set to discuss international issues such as the situation in Cyrpus and the Turkish leader will meet business investors at the Chatham House think tank.