Who was the last Viceroy of India?

Lord Mountbatten

After the passing of the Government of India Act of 1858, The Governor-general of India was called the Viceroy of India.

Lord Canning, the then Governor-general was made the first Viceroy of India.
Lord Wavell was appointed the Viceroy of India in the year 1944. He was the second-last Viceroy of the country and was succeeded by Lord Mountbatten.
In February 1947, Wavell was replaced as Viceroy by Lord Mountbatten (thus, he became the last Viceroy of India).  Mountbatten called one last round of talks, but when these too proved inconclusive he announced that British India would be freed, but also divided.
From June 1948 to January 1950 C Rajagopalachari served as the first Indian Governor-General of India.
( The title of Viceroy was used during the period when India was a British colony and was ruled by the British monarch.)