He was a Fulbright Scholar at the University of California, Berkeley, where his thesis, contrasting American and Scandinavian diplomatic models, was published as a book.

Egeland first attracted attention as Secretary General of the Norwegian Red Cross when he pioneered the fight against the proliferation of small arms and joined the international campaign against landmines.

He co-initiated and co-organized the Norwegian channel between Israel and Palestine Liberation Organization (PLO) in 1992, which led to the Oslo Accord (Declaration of Principles) of September 1993.

He directed the Norwegian facilitation of the United Nations-led peace talks leading up to ceasefire agreement between the Government of Guatemala and the Unidad Revolucionaria Nacional Guatemalteca (URNG) guerrillas signed in Oslo in 1996.

Egeland focused his efforts in alleviating the needs of this sector of the population in complex emergency situations like the Lord's Resistance Army insurgency in northern Uganda, the Darfur region in Sudan and the Democratic Republic of Congo, where millions of displaced persons are affected.

He has also campaigned for addressing the needs of those affected by natural disasters, like the 2004 Indian Ocean tsunami and Hurricane Katrina, as well as raising awareness in issues such as gender mainstreaming, sexual exploitation and violence, and internal displacement.

[9][10] In early 2021, United Nations Secretary-General António Guterres appointed him to a three‑person Independent Senior Advisory Panel on Syria, alongside Erika Feller and Radhouane Noucier.

The panel was to provide Guterres with advice on how to strengthen the deconfliction mechanism operated by the Office for the Coordination of Humanitarian Affairs in the country.

[23] Initial response by the White House to Egeland's quote, taken out of context by the press as a direct attack on the United States (which at the time had donated $15 million), was very negative.

When reviewing the tangible, if non-monetary, assistance of the militaries of the United States, Australia, and other nations in providing disaster relief, Egeland remarked, "Those helicopters are worth their weight in gold now."

[25]During a visit to the Gaza Strip to survey the damage, Egeland was quoted as saying that the bombing of a power plant would affect schools and hospitals more than the militants.

"[27] Furthermore, in light of the escalating violence in late 2023, Egeland issued a statement emphasizing the immense suffering of innocent Palestinians due to indiscriminate bombardments and sieges.

He expressed deep concern over the inadequate humanitarian response, underscoring that world leaders' failure to act condemns future generations of Palestinians and Israelis to continued conflict.

[29][30] In 1989, Egeland wrote Impotent Superpower – Potent Small State, in which he portrayed Norway, which at the time devoted the highest percentage of its money to the development of any country in the world, as a "moral entrepreneur".

[36] In 2012, the Norwegian group Ylvis produced a parody/tribute rock song about Jan Egeland, hailing him as "the United Nations superhero man" and "a peacekeeping machine".