Who named the Murray river and the darling river?

Both the Murray River and the Darling River were named by explorer Charles Sturt.

The Darling River was named by Charles Sturt early in 1829. During an expedition in which he traced the Macquarie River and beyond, Sturt arrived suddenly at what he described as "a noble river". This was the Darling, which he named after Governor Ralph Darling.

The Murray River was originally called the Hume when it was discovered by Hume and Hovell in 1824. (Whether it was named by Hovell for his partner Hume, or by Hume for his father, remained a point of contention between the two for some time.) It became the Murray late in 1829 when Sturt discovered that the Murrumbidgee flowed into it, and charted the river. Sturt named it the Murray after Sir George Murray, Secretary of State for the Colonies at that time.

Murray River is Autralia's longest river at 2, 375 kilometers in length. It was named after Sir George Murray.

Darling River is the third longest river in Australia measuring 1, 472 kilometers in length and was discovered by an explorer named Charles Sturt in 1829 and was named after Sir Ralph Darling the governor of the New South Wales.