Lennox Lagu, born Mongameli Johnson Tshali (16 October 1938  – 7 September 2011) was a commander of Umkhonto we Sizwe (MK), the armed wing of the African National Congress (ANC).

Tshali joined the ANC and MK in 1961; he served in various capacities until his return to South Africa in 1992.

He served as an MK commander in the former Union of Soviet Socialist Republic (USSR), Tanzania, Angola, Zambia, Zimbabwe and Mozambique.

[2][3] In 1967–1968, Tshali was the deputy commander of the Luthuli Contingent which fought alongside Zimbabwean People’s Revolutionary Army (ZIPRA) forces in the Wankie Sipollilo campaign.

In 1994 Tshali was integrated into the SANDF where he obtained the rank of major general and served the South African Army as the leader of Project Juggernaut which dealt with issues of troop discipline.