The Eastern Province (Swahili: Mashariki) of Kenya was one of 8 Provinces of Kenya. Its northern boundary ran along with that of Ethiopia; the North Eastern Province and Coast Province lay to the east and south; and the remainder of Kenya's provinces, including Central Province, ran along its western border. The provincial capital was Embu.

On 16 July 2009, the province was sub-divided into three sub-provinces, namely Lower Eastern with Machakos as headquarters, Central Eastern with Meru as headquarters, and Upper Eastern with Marsabit as headquarters; however, those changes never took effect due to the political wrangles in the Kenyan coalition government at the time. The sub-division of provinces was carried out in all seven provinces of Kenya, excluding Nairobi. As of March 2013 after the Kenyan general election, 2013, the Eastern Province was subdivided into eight counties, namely:

Code	County	Former province	Area (km)	Population census 2009	Capital
10	Marsabit	Eastern	66,923.1	291,166	Marsabit
11	Isiolo	Eastern	25,336.1	143,294	Isiolo
12	Meru	Eastern	7,003	1,356,301	Meru
13	Tharaka-Nithi	Eastern	2,609.5	365,330	Chuka
14	Embu	Eastern	2,555.9	516,212	Embu
15	Kitui	Eastern	24,385.1	1,012,709	Kitui
16	Machakos	Eastern	5,952.9	1,098,584	Machakos
17	Makueni	Eastern	8,008.9	884,527	Wote
	Totals		140,698.6	5,668,123	-

The province was principally inhabited by the Meru, Kamba, Embu, and several pastoralist communities. In 1979, its population was 2.7 million; in 1999, 4,631,779 (according to the 1999 census) and in 2009 the province would have had a population of 5,668,123. In terms of area, it was the second largest province at (140,698.6 km) in Kenya.

Eastern Province of Kenya includes the Chalbi Desert, Mount Kenya, and the eastern half of Lake Turkana. The climate in the region is arid to semi-arid. Its most important permanent river is Ewaso Ng'iro.

• Makueni County
• Marsabit County
• Meru County
• Tharaka-Nithi County
• Kitui County
• Isiolo County
• Machakos County