"I am excited that today I have achieved my dream of going back to school," she said after her first day of classes at Edgbaston High School for Girls in Birmingham.
"I want all girls in the world to have this basic opportunity. I miss my classmates from Pakistan very much but I am looking forward to meeting my teachers and making new friends here in Birmingham," she added.
Malala has joined the girls in Year 9 and will be studying a full curriculum in preparation for selecting her subjects for GCSEs, the school said in a statement.
It also asked the media to "allow her to attend school without intrusion and to respect the privacy of other pupils and parents".
Malala was returning home from school in Pakistan's north-western Swat district on October 9 last year when gunmen stopped her bus and shot her in the head and the chest.
The bullet entered just above her left eye, running along her jaw and "grazing" her brain. Surgeons in Pakistan removed the bullet before she was air-lifted to the UK for life-saving treatment at Queen Elizabeth Hospital in Birmingham.
The Taliban had said it shot Malala for "promoting secularism", sparking international outrage. She is set to secure permanent residence in the UK after her father, Ziauddin Yousafzai, was given a job with the Pakistani consulate in Birmingham for the next three years.
Speaking in a recorded video message for the first time since the attack, Malala had announced a fund to be used to help provide education for all young people.
She was also nominated for the 2013 Nobel Peace Prize earlier this month.
"She is a candidate who embodies several causes: the rights of girls and women, education, youth, and the fight against extremism," said prize observer Kristian Berg Harpviken, the head of the Peace Research Institute of Oslo.